apr_common.m4

dnl -------------------------------------------------------- -*- autoconf -*-
dnl Licensed to the Apache Software Foundation (ASF) under one or more
dnl contributor license agreements.  See the NOTICE file distributed with
dnl this work for additional information regarding copyright ownership.
dnl The ASF licenses this file to You under the Apache License, Version 2.0
dnl (the "License"); you may not use this file except in compliance with
dnl the License.  You may obtain a copy of the License at
dnl
dnl     http://www.apache.org/licenses/LICENSE-2.0
dnl
dnl Unless required by applicable law or agreed to in writing, software
dnl distributed under the License is distributed on an "AS IS" BASIS,
dnl WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
dnl See the License for the specific language governing permissions and
dnl limitations under the License.

dnl
dnl apr_common.m4: APR's general-purpose autoconf macros
dnl

dnl
dnl APR_CONFIG_NICE(filename)
dnl
dnl Saves a snapshot of the configure command-line for later reuse
dnl
AC_DEFUN([APR_CONFIG_NICE],[
  rm -f $1
  cat >$1<<EOF
#! /bin/sh
#
# Created by configure

EOF
  if test -n "$CC"; then
    echo "CC=\"$CC\"; export CC" >> $1
  fi
  if test -n "$CFLAGS"; then
    echo "CFLAGS=\"$CFLAGS\"; export CFLAGS" >> $1
  fi
  if test -n "$CPPFLAGS"; then
    echo "CPPFLAGS=\"$CPPFLAGS\"; export CPPFLAGS" >> $1
  fi
  if test -n "$LDFLAGS"; then
    echo "LDFLAGS=\"$LDFLAGS\"; export LDFLAGS" >> $1
  fi
  if test -n "$LTFLAGS"; then
    echo "LTFLAGS=\"$LTFLAGS\"; export LTFLAGS" >> $1
  fi
  if test -n "$LIBS"; then
    echo "LIBS=\"$LIBS\"; export LIBS" >> $1
  fi
  if test -n "$INCLUDES"; then
    echo "INCLUDES=\"$INCLUDES\"; export INCLUDES" >> $1
  fi
  if test -n "$NOTEST_CFLAGS"; then
    echo "NOTEST_CFLAGS=\"$NOTEST_CFLAGS\"; export NOTEST_CFLAGS" >> $1
  fi
  if test -n "$NOTEST_CPPFLAGS"; then
    echo "NOTEST_CPPFLAGS=\"$NOTEST_CPPFLAGS\"; export NOTEST_CPPFLAGS" >> $1
  fi
  if test -n "$NOTEST_LDFLAGS"; then
    echo "NOTEST_LDFLAGS=\"$NOTEST_LDFLAGS\"; export NOTEST_LDFLAGS" >> $1
  fi
  if test -n "$NOTEST_LIBS"; then
    echo "NOTEST_LIBS=\"$NOTEST_LIBS\"; export NOTEST_LIBS" >> $1
  fi

  # Retrieve command-line arguments.
  eval "set x $[0] $ac_configure_args"
  shift

  for arg
  do
    APR_EXPAND_VAR(arg, $arg)
    echo "\"[$]arg\" \\" >> $1
  done
  echo '"[$]@"' >> $1
  chmod +x $1
])dnl

dnl APR_MKDIR_P_CHECK(fallback-mkdir-p)
dnl checks whether mkdir -p works
AC_DEFUN([APR_MKDIR_P_CHECK],[
  AC_CACHE_CHECK(for working mkdir -p, ac_cv_mkdir_p,[
    test -d conftestdir && rm -rf conftestdir
    mkdir -p conftestdir/somedir >/dev/null 2>&1
    if test -d conftestdir/somedir; then
      ac_cv_mkdir_p=yes
    else
      ac_cv_mkdir_p=no
    fi
    rm -rf conftestdir
  ])
  if test "$ac_cv_mkdir_p" = "yes"; then
      mkdir_p="mkdir -p"
  else
      mkdir_p="$1"
  fi
])

dnl
dnl APR_SUBDIR_CONFIG(dir [, sub-package-cmdline-args, args-to-drop])
dnl
dnl dir: directory to find configure in
dnl sub-package-cmdline-args: arguments to add to the invocation (optional)
dnl args-to-drop: arguments to drop from the invocation (optional)
dnl
dnl Note: This macro relies on ac_configure_args being set properly.
dnl
dnl The args-to-drop argument is shoved into a case statement, so
dnl multiple arguments can be separated with a |.
dnl
dnl Note: Older versions of autoconf do not single-quote args, while 2.54+
dnl places quotes around every argument.  So, if you want to drop the
dnl argument called --enable-layout, you must pass the third argument as:
dnl [--enable-layout=*|\'--enable-layout=*]
dnl
dnl Trying to optimize this is left as an exercise to the reader who wants
dnl to put up with more autoconf craziness.  I give up.
dnl
AC_DEFUN([APR_SUBDIR_CONFIG], [
  # save our work to this point; this allows the sub-package to use it
  AC_CACHE_SAVE

  echo "configuring package in $1 now"
  ac_popdir=`pwd`
  apr_config_subdirs="$1"
  test -d $1 || $mkdir_p $1
  ac_abs_srcdir=`(cd $srcdir/$1 && pwd)`
  cd $1

changequote(, )dnl
      # A "../" for each directory in /$config_subdirs.
      ac_dots=`echo $apr_config_subdirs|sed -e 's%^\./%%' -e 's%[^/]$%&/%' -e 's%[^/]*/%../%g'`
changequote([, ])dnl

  # Make the cache file pathname absolute for the subdirs
  # required to correctly handle subdirs that might actually
  # be symlinks
  case "$cache_file" in
  /*) # already absolute
    ac_sub_cache_file=$cache_file ;;
  *)  # Was relative path.
    ac_sub_cache_file="$ac_popdir/$cache_file" ;;
  esac

  ifelse($3, [], [apr_configure_args=$ac_configure_args],[
  apr_configure_args=
  apr_sep=
  for apr_configure_arg in $ac_configure_args
  do
    case "$apr_configure_arg" in
      $3)
        continue ;;
    esac
    apr_configure_args="$apr_configure_args$apr_sep'$apr_configure_arg'"
    apr_sep=" "
  done
  ])

  # autoconf doesn't add --silent to ac_configure_args; explicitly pass it
  test "x$silent" = "xyes" && apr_configure_args="$apr_configure_args --silent"

  dnl The eval makes quoting arguments work - specifically $2 where the
  dnl quoting mechanisms used is "" rather than [].
  dnl
  dnl We need to execute another shell because some autoconf/shell combinations
  dnl will choke after doing repeated APR_SUBDIR_CONFIG()s.  (Namely Solaris
  dnl and autoconf-2.54+)
  if eval $SHELL $ac_abs_srcdir/configure $apr_configure_args --cache-file=$ac_sub_cache_file --srcdir=$ac_abs_srcdir $2
  then :
    echo "$1 configured properly"
  else
    echo "configure failed for $1"
    exit 1
  fi

  cd $ac_popdir

  # grab any updates from the sub-package
  AC_CACHE_LOAD
])dnl

dnl
dnl APR_SAVE_THE_ENVIRONMENT(variable_name)
dnl
dnl Stores the variable (usually a Makefile macro) for later restoration
dnl
AC_DEFUN([APR_SAVE_THE_ENVIRONMENT],[
  apr_ste_save_$1="$$1"
])dnl

dnl
dnl APR_RESTORE_THE_ENVIRONMENT(variable_name, prefix_)
dnl
dnl Uses the previously saved variable content to figure out what configure
dnl has added to the variable, moving the new bits to prefix_variable_name
dnl and restoring the original variable contents.  This makes it possible
dnl for a user to override configure when it does something stupid.
dnl
AC_DEFUN([APR_RESTORE_THE_ENVIRONMENT],[
if test "x$apr_ste_save_$1" = "x"; then
  $2$1="$$1"
  $1=
else
  if test "x$apr_ste_save_$1" = "x$$1"; then
    $2$1=
  else
    $2$1=`echo $$1 | sed -e "s%${apr_ste_save_$1}%%"`
    $1="$apr_ste_save_$1"
  fi
fi
if test "x$silent" != "xyes"; then
  echo "  restoring $1 to \"$$1\""
  echo "  setting $2$1 to \"$$2$1\""
fi
AC_SUBST($2$1)
])dnl

dnl
dnl APR_SETIFNULL(variable, value)
dnl
dnl  Set variable iff it's currently null
dnl
AC_DEFUN([APR_SETIFNULL],[
  if test -z "$$1"; then
    test "x$silent" != "xyes" && echo "  setting $1 to \"$2\""
    $1="$2"
  fi
])dnl

dnl
dnl APR_SETVAR(variable, value)
dnl
dnl  Set variable no matter what
dnl
AC_DEFUN([APR_SETVAR],[
  test "x$silent" != "xyes" && echo "  forcing $1 to \"$2\""
  $1="$2"
])dnl

dnl
dnl APR_ADDTO(variable, value)
dnl
dnl  Add value to variable
dnl
AC_DEFUN([APR_ADDTO],[
  if test "x$$1" = "x"; then
    test "x$silent" != "xyes" && echo "  setting $1 to \"$2\""
    $1="$2"
  else
    apr_addto_bugger="$2"
    for i in $apr_addto_bugger; do
      apr_addto_duplicate="0"
      for j in $$1; do
        if test "x$i" = "x$j"; then
          apr_addto_duplicate="1"
          break
        fi
      done
      if test $apr_addto_duplicate = "0"; then
        test "x$silent" != "xyes" && echo "  adding \"$i\" to $1"
        $1="$$1 $i"
      fi
    done
  fi
])dnl

dnl
dnl APR_REMOVEFROM(variable, value)
dnl
dnl Remove a value from a variable
dnl
AC_DEFUN([APR_REMOVEFROM],[
  if test "x$$1" = "x$2"; then
    test "x$silent" != "xyes" && echo "  nulling $1"
    $1=""
  else
    apr_new_bugger=""
    apr_removed=0
    for i in $$1; do
      if test "x$i" != "x$2"; then
        apr_new_bugger="$apr_new_bugger $i"
      else
        apr_removed=1
      fi
    done
    if test $apr_removed = "1"; then
      test "x$silent" != "xyes" && echo "  removed \"$2\" from $1"
      $1=$apr_new_bugger
    fi
  fi
]) dnl

dnl
dnl APR_CHECK_DEFINE_FILES( symbol, header_file [header_file ...] )
dnl
AC_DEFUN([APR_CHECK_DEFINE_FILES],[
  AC_CACHE_CHECK([for $1 in $2],ac_cv_define_$1,[
    ac_cv_define_$1=no
    for curhdr in $2
    do
      AC_EGREP_CPP(YES_IS_DEFINED, [
#include <$curhdr>
#ifdef $1
YES_IS_DEFINED
#endif
      ], ac_cv_define_$1=yes)
    done
  ])
  if test "$ac_cv_define_$1" = "yes"; then
    AC_DEFINE(HAVE_$1, 1, [Define if $1 is defined])
  fi
])


dnl
dnl APR_CHECK_DEFINE(symbol, header_file)
dnl
AC_DEFUN([APR_CHECK_DEFINE],[
  AC_CACHE_CHECK([for $1 in $2],ac_cv_define_$1,[
    AC_EGREP_CPP(YES_IS_DEFINED, [
#include <$2>
#ifdef $1
YES_IS_DEFINED
#endif
    ], ac_cv_define_$1=yes, ac_cv_define_$1=no)
  ])
  if test "$ac_cv_define_$1" = "yes"; then
    AC_DEFINE(HAVE_$1, 1, [Define if $1 is defined in $2])
  fi
])

dnl
dnl APR_CHECK_APR_DEFINE( symbol )
dnl
AC_DEFUN([APR_CHECK_APR_DEFINE],[
apr_old_cppflags=$CPPFLAGS
CPPFLAGS="$CPPFLAGS $INCLUDES"
AC_EGREP_CPP(YES_IS_DEFINED, [
#include <apr.h>
#if $1
YES_IS_DEFINED
#endif
], ac_cv_define_$1=yes, ac_cv_define_$1=no)
CPPFLAGS=$apr_old_cppflags
])

dnl APR_CHECK_FILE(filename); set ac_cv_file_filename to
dnl "yes" if 'filename' is readable, else "no".
dnl @deprecated! - use AC_CHECK_FILE instead
AC_DEFUN([APR_CHECK_FILE], [
dnl Pick a safe variable name
define([apr_cvname], ac_cv_file_[]translit([$1], [./+-], [__p_]))
AC_CACHE_CHECK([for $1], [apr_cvname],
[if test -r $1; then
   apr_cvname=yes
 else
   apr_cvname=no
 fi])
])

define(APR_IFALLYES,[dnl
ac_rc=yes
for ac_spec in $1; do
    ac_type=`echo "$ac_spec" | sed -e 's/:.*$//'`
    ac_item=`echo "$ac_spec" | sed -e 's/^.*://'`
    case $ac_type in
        header )
            ac_item=`echo "$ac_item" | sed 'y%./+-%__p_%'`
            ac_var="ac_cv_header_$ac_item"
            ;;
        file )
            ac_item=`echo "$ac_item" | sed 'y%./+-%__p_%'`
            ac_var="ac_cv_file_$ac_item"
            ;;
        func )   ac_var="ac_cv_func_$ac_item"   ;;
        struct ) ac_var="ac_cv_struct_$ac_item" ;;
        define ) ac_var="ac_cv_define_$ac_item" ;;
        custom ) ac_var="$ac_item" ;;
    esac
    eval "ac_val=\$$ac_var"
    if test ".$ac_val" != .yes; then
        ac_rc=no
        break
    fi
done
if test ".$ac_rc" = .yes; then
    :
    $2
else
    :
    $3
fi
])


define(APR_BEGIN_DECISION,[dnl
ac_decision_item='$1'
ac_decision_msg='FAILED'
ac_decision=''
])


AC_DEFUN([APR_DECIDE],[dnl
dnl Define the flag (or not) in apr_private.h via autoheader
AH_TEMPLATE($1, [Define if $2 will be used])
ac_decision='$1'
ac_decision_msg='$2'
ac_decision_$1=yes
ac_decision_$1_msg='$2'
])


define(APR_DECISION_OVERRIDE,[dnl
    ac_decision=''
    for ac_item in $1; do
         eval "ac_decision_this=\$ac_decision_${ac_item}"
         if test ".$ac_decision_this" = .yes; then
             ac_decision=$ac_item
             eval "ac_decision_msg=\$ac_decision_${ac_item}_msg"
         fi
    done
])


define(APR_DECISION_FORCE,[dnl
ac_decision="$1"
eval "ac_decision_msg=\"\$ac_decision_${ac_decision}_msg\""
])


define(APR_END_DECISION,[dnl
if test ".$ac_decision" = .; then
    echo "[$]0:Error: decision on $ac_decision_item failed" 1>&2
    exit 1
else
    if test ".$ac_decision_msg" = .; then
        ac_decision_msg="$ac_decision"
    fi
    AC_DEFINE_UNQUOTED(${ac_decision_item})
    AC_MSG_RESULT([decision on $ac_decision_item... $ac_decision_msg])
fi
])


dnl
dnl APR_CHECK_SIZEOF_EXTENDED(INCLUDES, TYPE [, CROSS_SIZE])
dnl
dnl A variant of AC_CHECK_SIZEOF which allows the checking of
dnl sizes of non-builtin types
dnl
AC_DEFUN([APR_CHECK_SIZEOF_EXTENDED],
[changequote(<<,>>)dnl
dnl The name to #define
define(<<AC_TYPE_NAME>>, translit(sizeof_$2, [a-z *], [A-Z_P]))dnl
dnl The cache variable
define(<<AC_CV_NAME>>, translit(ac_cv_sizeof_$2, [ *],[<p>]))dnl
changequote([, ])dnl
AC_MSG_CHECKING(size of $2)
AC_CACHE_VAL(AC_CV_NAME,
[AC_TRY_RUN([#include <stdio.h>
$1
#include <stdlib.h>

int main(void)
{
  FILE *f=fopen("conftestval","w");
  if (!f) exit(1);
  fprintf(f, "%d\n", sizeof($2));
  exit(0);
}], AC_CV_NAME=`cat conftestval`, AC_CV_NAME=0, ifelse([$3],,,
AC_CV_NAME=$3))])dnl
AC_MSG_RESULT($AC_CV_NAME)
AC_DEFINE_UNQUOTED(AC_TYPE_NAME, $AC_CV_NAME, [The size of ]$2)
undefine([AC_TYPE_NAME])dnl
undefine([AC_CV_NAME])dnl
])


dnl
dnl APR_TRY_COMPILE_NO_WARNING(INCLUDES, FUNCTION-BODY,
dnl             [ACTIONS-IF-NO-WARNINGS], [ACTIONS-IF-WARNINGS])
dnl
dnl Tries a compile test with warnings activated so that the result
dnl is false if the code doesn't compile cleanly.  For compilers
dnl where it is not known how to activate a "fail-on-error" mode,
dnl it is undefined which of the sets of actions will be run.
dnl
AC_DEFUN([APR_TRY_COMPILE_NO_WARNING],
[apr_save_CFLAGS=$CFLAGS
 CFLAGS="$CFLAGS $CFLAGS_WARN"
 if test "$ac_cv_prog_gcc" = "yes"; then 
   CFLAGS="$CFLAGS -Werror"
 fi
 AC_COMPILE_IFELSE([AC_LANG_SOURCE([
  [#include "confdefs.h"
  ]
  [[$1]]
  [int main(int argc, const char *const *argv) {]
  [[$2]]
  [   return 0; }]])],
  [$3], [$4])
 CFLAGS=$apr_save_CFLAGS
])

dnl
dnl APR_CHECK_STRERROR_R_RC
dnl
dnl  Decide which style of retcode is used by this system's 
dnl  strerror_r().  It either returns int (0 for success, -1
dnl  for failure), or it returns a pointer to the error 
dnl  string.
dnl
dnl
AC_DEFUN([APR_CHECK_STRERROR_R_RC],[
AC_MSG_CHECKING(for type of return code from strerror_r)
AC_TRY_RUN([
#include <errno.h>
#include <string.h>
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
int main(void)
{
  char buf[1024];
  if (strerror_r(ERANGE, buf, sizeof buf) < 1) {
    exit(0);
  }
  else {
    exit(1);
  }
}], [
    ac_cv_strerror_r_rc_int=yes ], [
    ac_cv_strerror_r_rc_int=no ], [
    ac_cv_strerror_r_rc_int=no ] )
if test "x$ac_cv_strerror_r_rc_int" = xyes; then
  AC_DEFINE(STRERROR_R_RC_INT, 1, [Define if strerror returns int])
  msg="int"
else
  msg="pointer"
fi
AC_MSG_RESULT([$msg])
] )

dnl
dnl APR_CHECK_DIRENT_INODE
dnl
dnl  Decide if d_fileno or d_ino are available in the dirent
dnl  structure on this platform.  Single UNIX Spec says d_ino,
dnl  BSD uses d_fileno.  Undef to find the real beast.
dnl
AC_DEFUN([APR_CHECK_DIRENT_INODE], [
AC_CACHE_CHECK([for inode member of struct dirent], apr_cv_dirent_inode, [
apr_cv_dirent_inode=no
AC_TRY_COMPILE([
#include <sys/types.h>
#include <dirent.h>
],[
#ifdef d_ino
#undef d_ino
#endif
struct dirent de; de.d_fileno;
], apr_cv_dirent_inode=d_fileno)
if test "$apr_cv_dirent_inode" = "no"; then
AC_TRY_COMPILE([
#include <sys/types.h>
#include <dirent.h>
],[
#ifdef d_fileno
#undef d_fileno
#endif
struct dirent de; de.d_ino;
], apr_cv_dirent_inode=d_ino)
fi
])
if test "$apr_cv_dirent_inode" != "no"; then
  AC_DEFINE_UNQUOTED(DIRENT_INODE, $apr_cv_dirent_inode, 
    [Define if struct dirent has an inode member])
fi
])

dnl
dnl APR_CHECK_DIRENT_TYPE
dnl
dnl  Decide if d_type is available in the dirent structure 
dnl  on this platform.  Not part of the Single UNIX Spec.
dnl  Note that this is worthless without DT_xxx macros, so
dnl  look for one while we are at it.
dnl
AC_DEFUN([APR_CHECK_DIRENT_TYPE],[
AC_CACHE_CHECK([for file type member of struct dirent], apr_cv_dirent_type,[
apr_cv_dirent_type=no
AC_TRY_COMPILE([
#include <sys/types.h>
#include <dirent.h>
],[
struct dirent de; de.d_type = DT_REG;
], apr_cv_dirent_type=d_type)
])
if test "$apr_cv_dirent_type" != "no"; then
  AC_DEFINE_UNQUOTED(DIRENT_TYPE, $apr_cv_dirent_type, 
    [Define if struct dirent has a d_type member]) 
fi
])

dnl the following is a newline, a space, a tab, and a backslash (the
dnl backslash is used by the shell to skip newlines, but m4 sees it;
dnl treat it like whitespace).
dnl WARNING: don't reindent these lines, or the space/tab will be lost!
define([apr_whitespace],[
 	\])

dnl
dnl APR_COMMA_ARGS(ARG1 ...)
dnl  convert the whitespace-separated arguments into comman-separated
dnl  arguments.
dnl
dnl APR_FOREACH(CODE-BLOCK, ARG1, ARG2, ...)
dnl  subsitute CODE-BLOCK for each ARG[i]. "eachval" will be set to ARG[i]
dnl  within each iteration.
dnl
changequote({,})
define({APR_COMMA_ARGS},{patsubst([$}{1],[[}apr_whitespace{]+],[,])})
define({APR_FOREACH},
  {ifelse($}{2,,,
          [define([eachval],
                  $}{2)$}{1[]APR_FOREACH([$}{1],
                                         builtin([shift],
                                                 builtin([shift], $}{@)))])})
changequote([,])

dnl APR_FLAG_HEADERS(HEADER-FILE ... [, FLAG-TO-SET ] [, "yes" ])
dnl  we set FLAG-TO-SET to 1 if we find HEADER-FILE, otherwise we set to 0
dnl  if FLAG-TO-SET is null, we automagically determine it's name
dnl  by changing all "/" to "_" in the HEADER-FILE and dropping
dnl  all "." and "-" chars. If the 3rd parameter is "yes" then instead of
dnl  setting to 1 or 0, we set FLAG-TO-SET to yes or no.
dnl  
AC_DEFUN([APR_FLAG_HEADERS],[
AC_CHECK_HEADERS($1)
for aprt_i in $1
do
    ac_safe=`echo "$aprt_i" | sed 'y%./+-%__p_%'`
    aprt_2=`echo "$aprt_i" | sed -e 's%/%_%g' -e 's/\.//g' -e 's/-//g'`
    if eval "test \"`echo '$ac_cv_header_'$ac_safe`\" = yes"; then
       eval "ifelse($2,,$aprt_2,$2)=ifelse($3,yes,yes,1)"
    else
       eval "ifelse($2,,$aprt_2,$2)=ifelse($3,yes,no,0)"
    fi
done
])

dnl APR_FLAG_FUNCS(FUNC ... [, FLAG-TO-SET] [, "yes" ])
dnl  if FLAG-TO-SET is null, we automagically determine it's name
dnl  prepending "have_" to the function name in FUNC, otherwise
dnl  we use what's provided as FLAG-TO-SET. If the 3rd parameter
dnl  is "yes" then instead of setting to 1 or 0, we set FLAG-TO-SET
dnl  to yes or no.
dnl
AC_DEFUN([APR_FLAG_FUNCS],[
AC_CHECK_FUNCS($1)
for aprt_j in $1
do
    aprt_3="have_$aprt_j"
    if eval "test \"`echo '$ac_cv_func_'$aprt_j`\" = yes"; then
       eval "ifelse($2,,$aprt_3,$2)=ifelse($3,yes,yes,1)"
    else
       eval "ifelse($2,,$aprt_3,$2)=ifelse($3,yes,no,0)"
    fi
done
])

dnl Iteratively interpolate the contents of the second argument
dnl until interpolation offers no new result. Then assign the
dnl final result to $1.
dnl
dnl Example:
dnl
dnl foo=1
dnl bar='${foo}/2'
dnl baz='${bar}/3'
dnl APR_EXPAND_VAR(fraz, $baz)
dnl   $fraz is now "1/2/3"
dnl 
AC_DEFUN([APR_EXPAND_VAR],[
ap_last=
ap_cur="$2"
while test "x${ap_cur}" != "x${ap_last}";
do
  ap_last="${ap_cur}"
  ap_cur=`eval "echo ${ap_cur}"`
done
$1="${ap_cur}"
])

dnl
dnl Removes the value of $3 from the string in $2, strips of any leading
dnl slashes, and returns the value in $1.
dnl
dnl Example:
dnl orig_path="${prefix}/bar"
dnl APR_PATH_RELATIVE(final_path, $orig_path, $prefix)
dnl    $final_path now contains "bar"
AC_DEFUN([APR_PATH_RELATIVE],[
ap_stripped=`echo $2 | sed -e "s#^$3##"`
# check if the stripping was successful
if test "x$2" != "x${ap_stripped}"; then
    # it was, so strip of any leading slashes
    $1="`echo ${ap_stripped} | sed -e 's#^/*##'`"
else
    # it wasn't so return the original
    $1="$2"
fi
])

dnl APR_HELP_STRING(LHS, RHS)
dnl Autoconf 2.50 can not handle substr correctly.  It does have 
dnl AC_HELP_STRING, so let's try to call it if we can.
dnl Note: this define must be on one line so that it can be properly returned
dnl as the help string.  When using this macro with a multi-line RHS, ensure
dnl that you surround the macro invocation with []s
AC_DEFUN([APR_HELP_STRING],[ifelse(regexp(AC_ACVERSION, 2\.1), -1, AC_HELP_STRING([$1],[$2]),[  ][$1] substr([                       ],len($1))[$2])])

dnl
dnl APR_LAYOUT(configlayout, layoutname [, extravars])
dnl
AC_DEFUN([APR_LAYOUT],[
  if test ! -f $srcdir/config.layout; then
    echo "** Error: Layout file $srcdir/config.layout not found"
    echo "** Error: Cannot use undefined layout '$LAYOUT'"
    exit 1
  fi
  # Catch layout names including a slash which will otherwise
  # confuse the heck out of the sed script.
  case $2 in
  */*) 
    echo "** Error: $2 is not a valid layout name"
    exit 1 ;;
  esac
  pldconf=./config.pld
  changequote({,})
  sed -e "1s/[ 	]*<[lL]ayout[ 	]*$2[ 	]*>[ 	]*//;1t" \
      -e "1,/[ 	]*<[lL]ayout[ 	]*$2[ 	]*>[ 	]*/d" \
      -e '/[ 	]*<\/Layout>[ 	]*/,$d' \
      -e "s/^[ 	]*//g" \
      -e "s/:[ 	]*/=\'/g" \
      -e "s/[ 	]*$/'/g" \
      $1 > $pldconf
  layout_name=$2
  if test ! -s $pldconf; then
    echo "** Error: unable to find layout $layout_name"
    exit 1
  fi
  . $pldconf
  rm $pldconf
  for var in prefix exec_prefix bindir sbindir libexecdir mandir \
             sysconfdir datadir includedir localstatedir runtimedir \
             logfiledir libdir installbuilddir libsuffix $3; do
    eval "val=\"\$$var\""
    case $val in
      *+)
        val=`echo $val | sed -e 's;\+$;;'`
        eval "$var=\"\$val\""
        autosuffix=yes
        ;;
      *)
        autosuffix=no
        ;;
    esac
    val=`echo $val | sed -e 's:\(.\)/*$:\1:'`
    val=`echo $val | sed -e 's:[\$]\([a-z_]*\):${\1}:g'`
    if test "$autosuffix" = "yes"; then
      if echo $val | grep apache >/dev/null; then
        addtarget=no
      else
        addtarget=yes
      fi
      if test "$addtarget" = "yes"; then
        val="$val/apache2"
      fi
    fi
    eval "$var='$val'"
  done
  changequote([,])
])dnl

dnl
dnl APR_ENABLE_LAYOUT(default layout name [, extra vars])
dnl
AC_DEFUN([APR_ENABLE_LAYOUT],[
AC_ARG_ENABLE(layout,
[  --enable-layout=LAYOUT],[
  LAYOUT=$enableval
])

if test -z "$LAYOUT"; then
  LAYOUT="$1"
fi
APR_LAYOUT($srcdir/config.layout, $LAYOUT, $2)

AC_MSG_CHECKING(for chosen layout)
AC_MSG_RESULT($layout_name)
])


dnl
dnl APR_PARSE_ARGUMENTS
dnl a reimplementation of autoconf's argument parser,
dnl used here to allow us to co-exist layouts and argument based
dnl set ups.
AC_DEFUN([APR_PARSE_ARGUMENTS],[
ac_prev=
# Retrieve the command-line arguments.  The eval is needed because
# the arguments are quoted to preserve accuracy.
eval "set x $ac_configure_args"
shift
for ac_option
do
  # If the previous option needs an argument, assign it.
  if test -n "$ac_prev"; then
    eval "$ac_prev=\$ac_option"
    ac_prev=
    continue
  fi

  ac_optarg=`expr "x$ac_option" : 'x[[^=]]*=\(.*\)'`

  case $ac_option in

  -bindir | --bindir | --bindi | --bind | --bin | --bi)
    ac_prev=bindir ;;
  -bindir=* | --bindir=* | --bindi=* | --bind=* | --bin=* | --bi=*)
    bindir="$ac_optarg" ;;

  -datadir | --datadir | --datadi | --datad | --data | --dat | --da)
    ac_prev=datadir ;;
  -datadir=* | --datadir=* | --datadi=* | --datad=* | --data=* | --dat=* \
  | --da=*)
    datadir="$ac_optarg" ;;

  -exec-prefix | --exec_prefix | --exec-prefix | --exec-prefi \
  | --exec-pref | --exec-pre | --exec-pr | --exec-p | --exec- \
  | --exec | --exe | --ex)
    ac_prev=exec_prefix ;;
  -exec-prefix=* | --exec_prefix=* | --exec-prefix=* | --exec-prefi=* \
  | --exec-pref=* | --exec-pre=* | --exec-pr=* | --exec-p=* | --exec-=* \
  | --exec=* | --exe=* | --ex=*)
    exec_prefix="$ac_optarg" ;;

  -includedir | --includedir | --includedi | --included | --include \
  | --includ | --inclu | --incl | --inc)
    ac_prev=includedir ;;
  -includedir=* | --includedir=* | --includedi=* | --included=* | --include=* \
  | --includ=* | --inclu=* | --incl=* | --inc=*)
    includedir="$ac_optarg" ;;

  -infodir | --infodir | --infodi | --infod | --info | --inf)
    ac_prev=infodir ;;
  -infodir=* | --infodir=* | --infodi=* | --infod=* | --info=* | --inf=*)
    infodir="$ac_optarg" ;;

  -libdir | --libdir | --libdi | --libd)
    ac_prev=libdir ;;
  -libdir=* | --libdir=* | --libdi=* | --libd=*)
    libdir="$ac_optarg" ;;

  -libexecdir | --libexecdir | --libexecdi | --libexecd | --libexec \
  | --libexe | --libex | --libe)
    ac_prev=libexecdir ;;
  -libexecdir=* | --libexecdir=* | --libexecdi=* | --libexecd=* | --libexec=* \
  | --libexe=* | --libex=* | --libe=*)
    libexecdir="$ac_optarg" ;;

  -localstatedir | --localstatedir | --localstatedi | --localstated \
  | --localstate | --localstat | --localsta | --localst \
  | --locals | --local | --loca | --loc | --lo)
    ac_prev=localstatedir ;;
  -localstatedir=* | --localstatedir=* | --localstatedi=* | --localstated=* \
  | --localstate=* | --localstat=* | --localsta=* | --localst=* \
  | --locals=* | --local=* | --loca=* | --loc=* | --lo=*)
    localstatedir="$ac_optarg" ;;

  -mandir | --mandir | --mandi | --mand | --man | --ma | --m)
    ac_prev=mandir ;;
  -mandir=* | --mandir=* | --mandi=* | --mand=* | --man=* | --ma=* | --m=*)
    mandir="$ac_optarg" ;;

  -prefix | --prefix | --prefi | --pref | --pre | --pr | --p)
    ac_prev=prefix ;;
  -prefix=* | --prefix=* | --prefi=* | --pref=* | --pre=* | --pr=* | --p=*)
    prefix="$ac_optarg" ;;

  -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
    ac_prev=sbindir ;;
  -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
  | --sbi=* | --sb=*)
    sbindir="$ac_optarg" ;;

  -sharedstatedir | --sharedstatedir | --sharedstatedi \
  | --sharedstated | --sharedstate | --sharedstat | --sharedsta \
  | --sharedst | --shareds | --shared | --share | --shar \
  | --sha | --sh)
    ac_prev=sharedstatedir ;;
  -sharedstatedir=* | --sharedstatedir=* | --sharedstatedi=* \
  | --sharedstated=* | --sharedstate=* | --sharedstat=* | --sharedsta=* \
  | --sharedst=* | --shareds=* | --shared=* | --share=* | --shar=* \
  | --sha=* | --sh=*)
    sharedstatedir="$ac_optarg" ;;

  -sysconfdir | --sysconfdir | --sysconfdi | --sysconfd | --sysconf \
  | --syscon | --sysco | --sysc | --sys | --sy)
    ac_prev=sysconfdir ;;
  -sysconfdir=* | --sysconfdir=* | --sysconfdi=* | --sysconfd=* | --sysconf=* \
  | --syscon=* | --sysco=* | --sysc=* | --sys=* | --sy=*)
    sysconfdir="$ac_optarg" ;;

  esac
done

# Be sure to have absolute paths.
for ac_var in exec_prefix prefix
do
  eval ac_val=$`echo $ac_var`
  case $ac_val in
    [[\\/$]]* | ?:[[\\/]]* | NONE | '' ) ;;
    *)  AC_MSG_ERROR([expected an absolute path for --$ac_var: $ac_val]);;
  esac
done

])dnl

dnl
dnl APR_CHECK_DEPEND
dnl
dnl Determine what program we can use to generate .deps-style dependencies
dnl
AC_DEFUN([APR_CHECK_DEPEND],[
dnl Try to determine what depend program we can use
dnl All GCC-variants should have -MM.
dnl If not, then we can check on those, too.
if test "$GCC" = "yes"; then
  MKDEP='$(CC) -MM'
else
  rm -f conftest.c
dnl <sys/types.h> should be available everywhere!
  cat > conftest.c <<EOF
#include <sys/types.h>
  int main(void) { return 0; }
EOF
  MKDEP="true"
  for i in "$CC -MM" "$CC -M" "$CPP -MM" "$CPP -M" "cpp -M"; do
    AC_MSG_CHECKING([if $i can create proper make dependencies])
    if $i conftest.c 2>/dev/null | grep 'conftest.o: conftest.c' >/dev/null; then
      MKDEP=$i
      AC_MSG_RESULT(yes)
      break;
    fi
    AC_MSG_RESULT(no)
  done
  rm -f conftest.c
fi

AC_SUBST(MKDEP)
])