AC_PATH_LIB(LIBRARY [, MINIMUM-VERSION [, HEADERS [, CONFIG-SCRIPT [, MODULES [, ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND ]]]]]])
, 

2005-01-23

Roger Leigh <roger@whinlatter.uklinux.net>

AllPermissive
Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. Users of this software should generally follow the principles of the MIT License includings its disclaimer.

cryp.to ac-archive's Obsoleted (obsoleted)

• obsoleted Deprecated with the advent of pkg-config.

Runs a LIBRARY-config script and defines LIBRARY_CFLAGS and LIBRARY_LIBS, saving you from writing your own macro specific to your library.

The options:

$1 = LIBRARY             e.g. gtk, ncurses, z, gimpprint
$2 = MINIMUM-VERSION     x.y.z format e.g. 4.2.1
                         Add ' -nocheck' e.g. '4.2.1 -nocheck' to avoid
                         checking version with library-defined version
                         numbers (see below) i.e. --version only
$3 = CONFIG-SCRIPT       Name of libconfig script if not
                         LIBRARY-config
$4 = MODULES             List of module names to pass to LIBRARY-config.
                         It is probably best to use only one, to avoid
                         two version numbers being reported.
$5 = ACTION-IF-FOUND     Shell script to run if library is found
$6 = ACTION-IF-NOT-FOUND Shell script to run if library is not found

pkg-config will be used to obtain cflags, libs and version data by default. You must have a library.pc file installed. Two macros enable and disable pkgconfig support:

 AC_PATH_LIB_PKGCONFIG   Enable pkg-config support
 AC_PATH_LIB_LIBCONFIG   Disable pkg-config support

When pkg-config is enabled, CONFIG_SCRIPT will be ignored.

LIBRARY-config must support `--cflags' and `--libs' args. If MINIMUM-VERSION is specified, LIBRARY-config should also support the `--version' arg, and have version information embedded in its header as detailed below:

Macros:

#define LIBRARY_MAJOR_VERSION       (@LIBRARY_MAJOR_VERSION@)
#define LIBRARY_MINOR_VERSION       (@LIBRARY_MINOR_VERSION@)
#define LIBRARY_MICRO_VERSION       (@LIBRARY_MICRO_VERSION@)

Version numbers (defined in the library):

extern const unsigned int library_major_version;
extern const unsigned int library_minor_version;
extern const unsigned int library_micro_version;

If a different naming scheme is used, this may be specified with AC_PATH_LIB_REGISTER (see below). For example:

 AC_PATH_LIB_REGISTER([_AC_PATH_LIB_VERSION_PREFIX], [mylib])

If the header to include is not called LIBRARY/LIBRARY.h, an alternate header may be specified with AC_PATH_LIB_REGISTER. All changes are reset to the defaults when the macro completes.

If the above are not defined, then use ' -nocheck'.

If the `--with-library-[exec-]prefix' arguments to ./configure are given, it must also support `--prefix' and `--exec-prefix'. (In other words, it must be like gtk-config.)

If modules are to be used, LIBRARY-config must support modules.

For example:

AC_PATH_LIB(foo, 1.0.0)

would run `foo-config --version' and check that it is at least 1.0.0

If so, the following would then be defined:

 FOO_CFLAGS  to `foo-config --cflags`
 FOO_LIBS    to `foo-config --libs`
 FOO_VERSION to `foo-config --version`

Based on `AM_PATH_GTK' (gtk.m4) by Owen Taylor, and `AC_PATH_GENERIC' (ac_path_generic.m4) by Angus Lees <gusl@cse.unsw.edu.au>. pkg-config support based on AM_PATH_GTK_2_0 (gtk-2.0.m4) by Owen Taylor.

## Table of Contents:
## 1. The main macro
## 2. Core macros
## 3. Integrity checks
## 4. Error reporting
## 5. Feature macros


## ------------------ ##
## 1. The main macro. ##
## ------------------ ##


# AC_PATH_LIB(LIBRARY, MINIMUM-VERSION, HEADER, CONFIG-SCRIPT,
#              MODULES, ACTION-IF-FOUND, ACTION-IF-NOT-FOUND)
# -----------------------------------------------------------
# Check for the presence of libLIBRARY, with a minumum version
# MINIMUM-VERSION.
#
# If needed, use the libconfig script CONFIG-SCRIPT.  If the script
# needs extra modules specifying, pass them as MODULES.
#
# Run ACTION-IF-FOUND if the library is present and all tests pass, or
# ACTION-IF-NOT-FOUND if it is not present or any tests fail.
AC_DEFUN([AC_PATH_LIB],[# check for presence of lib$1
dnl We're going to need uppercase, lowercase and user-friendly
dnl versions of the string `LIBRARY', and long and cache variants.
m4_pushdef([UP], m4_translit([$1], [a-z], [A-Z]))dnl
m4_pushdef([DOWN], m4_translit([$1], [A-Z], [a-z]))dnl
m4_pushdef([LDOWN], ac_path_lib_[]DOWN)dnl
m4_pushdef([CACHE], ac_cv_path_lib_[]DOWN)dnl
m4_pushdef([ERRORLOG], error.[]DOWN[]test)dnl
_AC_PATH_LIB_INIT([$1], [$3], [$4])
_AC_PATH_LIB_CHECK([$1], [$2], [$5])
_AC_PATH_LIB_CHECK_TESTS([$2])
_AC_PATH_LIB_ERROR_DUMP
_AC_PATH_LIB_FINI([$6], [$7])
dnl Pop the macros we defined earlier.
m4_popdef([UP])dnl
m4_popdef([DOWN])dnl
m4_popdef([LDOWN])dnl
m4_popdef([CACHE])dnl
m4_popdef([ERRORLOG])dnl
])# AC_PATH_LIB




## --------------- ##
## 2. Core macros. ##
## --------------- ##


# _AC_PATH_LIB_INIT(LIBRARY, HEADER, CONFIG-SCRIPT)
# -----------------------------------------
# Initialisation of defaults and options.
# Remove error log from previous runs.
AC_DEFUN([_AC_PATH_LIB_INIT],
[_AC_PATH_LIB_DEFAULTS([$1], [$2], [$3])
_AC_PATH_LIB_OPTIONS
rm -f ERRORLOG
# Save variables in case check fails.
ac_save_[]UP[]_CFLAGS="$UP[]_CFLAGS"
ac_save_[]UP[]_LIBS="$UP[]_LIBS"
ac_save_[]UP[]_VERSION="$UP[]_VERSION"
])


# _AC_PATH_LIB_DEFAULTS(LIBRARY, HEADER, CONFIG-SCRIPT)
# -----------------------------------------------------
# Set up default behaviour.
AC_DEFUN([_AC_PATH_LIB_DEFAULTS],
[dnl Set up pkgconfig as default config script.
m4_ifdef([AC_PATH_LIB_USEPKGCONFIG],, [AC_PATH_LIB_PKGCONFIG])
dnl Set default header and config script names.
LDOWN[]_header="m4_default([$2], [$1/$1.h])"
LDOWN[]_config="m4_default([$3], [$1-config])"
ifdef([_AC_PATH_LIB_VERSION_PREFIX],,
      [m4_define([_AC_PATH_LIB_VERSION_PREFIX],
                 DOWN[_])
      ])
ifdef([_AC_PATH_LIB_VERSION_MAJOR],,
      [m4_define([_AC_PATH_LIB_VERSION_MAJOR],
                 [major])
      ])
ifdef([_AC_PATH_LIB_VERSION_MINOR],,
      [m4_define([_AC_PATH_LIB_VERSION_MINOR],
                 [minor])
      ])
ifdef([_AC_PATH_LIB_VERSION_MICRO],,
      [m4_define([_AC_PATH_LIB_VERSION_MICRO],
                 [micro])
      ])
ifdef([_AC_PATH_LIB_VERSION_SUFFIX],,
      [m4_define([_AC_PATH_LIB_VERSION_SUFFIX],
                 [_version])
      ])
ifdef([_AC_PATH_LIB_DEFVERSION_PREFIX],,
      [m4_define([_AC_PATH_LIB_DEFVERSION_PREFIX],
                 UP[_])
      ])
ifdef([_AC_PATH_LIB_DEFVERSION_MAJOR],,
      [m4_define([_AC_PATH_LIB_DEFVERSION_MAJOR],
                 [MAJOR])
      ])
ifdef([_AC_PATH_LIB_DEFVERSION_MINOR],,
      [m4_define([_AC_PATH_LIB_DEFVERSION_MINOR],
                 [MINOR])
      ])
ifdef([_AC_PATH_LIB_DEFVERSION_MICRO],,
      [m4_define([_AC_PATH_LIB_DEFVERSION_MICRO],
                 [MICRO])
      ])
ifdef([_AC_PATH_LIB_DEFVERSION_SUFFIX],,
      [m4_define([_AC_PATH_LIB_DEFVERSION_SUFFIX],
                 [_VERSION])
      ])
])# _AC_PATH_LIB_DEFAULTS


# _AC_PATH_LIB_OPTIONS
# --------------------
# configure options.
AC_DEFUN([_AC_PATH_LIB_OPTIONS],
[m4_if(AC_PATH_LIB_USEPKGCONFIG, [true], ,
[AC_ARG_WITH(DOWN-prefix,
            AC_HELP_STRING([--with-DOWN-prefix=PFX],
                           [prefix where UP is installed (optional)]),
            [LDOWN[]_config_prefix="$withval"],
            [LDOWN[]_config_prefix=""])dnl
AC_ARG_WITH(DOWN-exec-prefix,
            AC_HELP_STRING([--with-DOWN-exec-prefix=PFX],
                           [exec-prefix where UP is installed (optional)]),
            [LDOWN[]_config_exec_prefix="$withval"],
            [LDOWN[]_config_exec_prefix=""])dnl
])
AC_ARG_ENABLE(DOWN[]test,
              AC_HELP_STRING([--disable-DOWN[]test],
                             [do not try to compile and run a test UP program]),
              [LDOWN[]_test_enabled="no"],
              [LDOWN[]_test_enabled="yes"])dnl
])# _AC_PATH_LIB_OPTIONS


# _AC_PATH_LIB_CHECK(LIBRARY, MINIMUM-VERSION, MODULES)
# -----------------------------------------------------
# Obtain library CFLAGS, LIBS and VERSION information.  Cache results,
# but set avoidcache to no if config program is not available.  Break
# up available and minumum version into major, minor and micro version
# numbers.
AC_DEFUN([_AC_PATH_LIB_CHECK],
[
# Set up LIBRARY-config script parameters
m4_if([$3], , ,
      [LDOWN[]_config_args="$LDOWN[]_config_args $3"])
LDOWN[]_min_version=`echo "$2" | sed -e 's/ -nocheck//'`
m4_if([$2], , ,[if test "$LDOWN[]_min_version" = "$2" ; then
                  LDOWN[]_version_test_enabled="yes"
                fi])
m4_if(AC_PATH_LIB_USEPKGCONFIG, [true],
[LDOWN[]_config_args="$1 $LDOWN[]_config_args"
],
[  if test x$LDOWN[]_config_exec_prefix != x ; then
    LDOWN[]_config_args="$LDOWN[]_config_args --exec-prefix=$LDOWN[]_config_exec_prefix"
  fi
  if test x$LDOWN[]_config_prefix != x ; then
    LDOWN[]_config_args="$LDOWN[]_config_args --prefix=$LDOWN[]_config_prefix"
  fi
])
dnl set --version for libconfig or --modversion for pkgconfig
m4_if(AC_PATH_LIB_USEPKGCONFIG, [true],
      [AC_PATH_PROG(PKG_CONFIG, pkg-config, no)
       if test x$PKG_CONFIG != xno ; then
         if pkg-config --atleast-pkgconfig-version 0.7 ; then
           :
         else
           AC_PATH_LIB_ERROR([A new enough version of pkg-config was not found:])
           AC_PATH_LIB_ERROR([version 0.7 or better required.])
           AC_PATH_LIB_ERROR([See http://pkgconfig.sourceforge.net])
           PKG_CONFIG=no
         fi
       fi
       UP[]_CONFIG="$PKG_CONFIG"
       LDOWN[]_config="pkg-config"
       m4_pushdef([LIBCONFIG_CFLAGS], [--cflags])
       m4_pushdef([LIBCONFIG_LIBS], [--libs])
       m4_pushdef([LIBCONFIG_VERSION], [--modversion])
      ],
      [AC_PATH_PROG(UP[]_CONFIG, $LDOWN[]_config, no)
       m4_pushdef([LIBCONFIG_CFLAGS], [--cflags])
       m4_pushdef([LIBCONFIG_LIBS], [--libs])
       m4_pushdef([LIBCONFIG_VERSION], [--version])
       if test x$UP[]_CONFIG = xno ; then
         AC_PATH_LIB_ERROR([The $LDOWN[]_config script installed by UP could not be found.])
         AC_PATH_LIB_ERROR([If UP was installed in PREFIX, make sure PREFIX/bin is in])
         AC_PATH_LIB_ERROR([your path, or set the UP[]_CONFIG environment variable to the])
         AC_PATH_LIB_ERROR([full path to $LDOWN[]_config.])
       fi
      ])

if test x$UP[]_CONFIG = xno ; then
  LDOWN[]_present_avoidcache="no"
else
  LDOWN[]_present_avoidcache="yes"

  AC_CACHE_CHECK([for UP CFLAGS],
                 [CACHE[]_cflags],
                 [CACHE[]_cflags=`$UP[]_CONFIG $LDOWN[]_config_args LIBCONFIG_CFLAGS`])
  AC_CACHE_CHECK([for UP LIBS],
                 [CACHE[]_libs],
                 [CACHE[]_libs=`$UP[]_CONFIG $LDOWN[]_config_args LIBCONFIG_LIBS`])
  AC_CACHE_CHECK([for UP VERSION],
                 [CACHE[]_version],
                 [CACHE[]_version=`$UP[]_CONFIG $LDOWN[]_config_args LIBCONFIG_VERSION`])
  UP[]_CFLAGS="$CACHE[]_cflags"
  UP[]_LIBS="$CACHE[]_libs"
  UP[]_VERSION="$CACHE[]_version"
  LDOWN[]_config_major_version=`echo "$CACHE[]_version" | \
      sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\1/'`
  LDOWN[]_config_minor_version=`echo "$CACHE[]_version" | \
      sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\2/'`
  LDOWN[]_config_micro_version=`echo "$CACHE[]_version" | \
      sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\3/'`
  LDOWN[]_min_major_version=`echo "$LDOWN[]_min_version" | \
      sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\1/'`
  LDOWN[]_min_minor_version=`echo "$LDOWN[]_min_version" | \
      sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\2/'`
  LDOWN[]_min_micro_version=`echo "$LDOWN[]_min_version" | \
      sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\3/'`
fi
m4_popdef([LIBCONFIG_CFLAGS])dnl
m4_popdef([LIBCONFIG_LIBS])dnl
m4_popdef([LIBCONFIG_VERSION])dnl
])# _AC_PATH_LIB_CHECK


# _AC_PATH_LIB_FINI(ACTION-IF-FOUND, ACTION-IF-NOT-FOUND)
# -------------------------------------------------------
# Finish: report errors and define/substitute variables.  Run any
# user-supplied code for success or failure.  Restore defaults.
AC_DEFUN([_AC_PATH_LIB_FINI],
[dnl define variables and run extra code
UP[]_CFLAGS="$CACHE[]_cflags"
UP[]_LIBS="$CACHE[]_libs"
UP[]_VERSION="$CACHE[]_version"
AC_SUBST(UP[]_CFLAGS)dnl
AC_SUBST(UP[]_LIBS)dnl
AC_SUBST(UP[]_VERSION)dnl
# Run code which depends upon the test result.
if test x$CACHE[]_present = xyes ; then
  m4_if([$1], , :, [$1])
else
# Restore saved variables if test fails
  UP[]_CFLAGS="$ac_save_[]UP[]_CFLAGS"
  UP[]_LIBS="$ac_save_[]UP[]_LIBS"
  UP[]_VERSION="$ac_save_[]UP[]_VERSION"
  m4_if([$2], , :, [$2])
fi
dnl Restore defaults
AC_PATH_LIB_CHECK_REGISTER_DEFAULTS
AC_PATH_LIB_PKGCONFIG
])# _AC_PATH_LIB_FINI




## -------------------- ##
## 3. Integrity checks. ##
## -------------------- ##


# _AC_PATH_LIB_CHECK_TESTS(MINIMUM-VERSION)
# -----------------------------------------
# Now check if the installed UP is sufficiently new. (Also sanity
# checks the results of DOWN-config to some extent
AC_DEFUN([_AC_PATH_LIB_CHECK_TESTS],
[AC_CACHE_CHECK([for UP - m4_if([$1], ,
                               [any version],
                               [version >= $LDOWN[]_min_version])],
               [CACHE[]_present],
[CACHE[]_present="$LDOWN[]_present_avoidcache"
if test x$CACHE[]_present = xyes -a x$LDOWN[]_test_enabled = xyes -a \
    x$LDOWN[]_version_test_enabled = xyes ; then
  m4_default([_AC_PATH_LIB_CHECK_TEST_COMPILE],
             [_AC_PATH_LIB_CHECK_TEST_COMPILE],
             [_AC_PATH_LIB_CHECK_TEST_COMPILE_DEFAULT])
else
  m4_default([_AC_PATH_LIB_CHECK_VERSION],
             [_AC_PATH_LIB_CHECK_VERSION],
             [_AC_PATH_LIB_CHECK_VERSION_DEFAULT])
# If the user allowed it, try linking with the library
  if test x$LDOWN[]_test_enabled = xyes ; then
    _AC_PATH_LIB_CHECK_LINK(, [
      CACHE[]_present="no"
      if test x$LDOWN[]_version_test_error = xyes ; then
        AC_PATH_LIB_ERROR
      fi
      AC_PATH_LIB_ERROR([The test program failed to compile or link.  See the file])
      AC_PATH_LIB_ERROR([config.log for the exact error that occured.  This usually])
      AC_PATH_LIB_ERROR([means UP was not installed, was incorrectly installed])
      AC_PATH_LIB_ERROR([or that you have moved UP since it was installed.  In])
      AC_PATH_LIB_ERROR([the latter case, you may want to edit the $LDOWN[]_config])
      AC_PATH_LIB_ERROR([script: $UP[]_CONFIG])
    ])
  fi
fi])
dnl end tests
])# _AC_PATH_LIB_CHECK_TESTS


# _AC_PATH_LIB_CHECK_TEST_COMPILE_DEFAULT
# ---------------------------------------
# Check if the installed UP is sufficiently new. (Also sanity checks
# the results of DOWN-config to some extent.  The test program must
# compile, link and run sucessfully
AC_DEFUN([_AC_PATH_LIB_CHECK_TEST_COMPILE],
[m4_pushdef([RUNLOG], run.[]DOWN[]test)dnl
m4_pushdef([MAJOR], _AC_PATH_LIB_VERSION_PREFIX[]_AC_PATH_LIB_VERSION_MAJOR[]_AC_PATH_LIB_VERSION_SUFFIX)dnl
m4_pushdef([MINOR], _AC_PATH_LIB_VERSION_PREFIX[]_AC_PATH_LIB_VERSION_MINOR[]_AC_PATH_LIB_VERSION_SUFFIX)dnl
m4_pushdef([MICRO], _AC_PATH_LIB_VERSION_PREFIX[]_AC_PATH_LIB_VERSION_MICRO[]_AC_PATH_LIB_VERSION_SUFFIX)dnl
m4_pushdef([DEFMAJOR], _AC_PATH_LIB_DEFVERSION_PREFIX[]_AC_PATH_LIB_DEFVERSION_MAJOR[]_AC_PATH_LIB_DEFVERSION_SUFFIX)dnl
m4_pushdef([DEFMINOR], _AC_PATH_LIB_DEFVERSION_PREFIX[]_AC_PATH_LIB_DEFVERSION_MINOR[]_AC_PATH_LIB_DEFVERSION_SUFFIX)dnl
m4_pushdef([DEFMICRO], _AC_PATH_LIB_DEFVERSION_PREFIX[]_AC_PATH_LIB_DEFVERSION_MICRO[]_AC_PATH_LIB_DEFVERSION_SUFFIX)dnl
  ac_save_CFLAGS="$CFLAGS"
  ac_save_LIBS="$LIBS"
  CFLAGS="$CFLAGS $UP[]_CFLAGS"
  LIBS="$UP[]_LIBS $LIBS"
  rm -f RUNLOG
  AC_TRY_RUN([
#include <$]LDOWN[_header>
#include <stdio.h>
#include <stdlib.h>

/*
 * XXX FIXME Francesco:
 *   This is a pigsty patch for undefined strdup (defined in string.h).
 *   Maybe we should look for strdup() or wrapping it using functions
 *   like malloc && strcpy().
 */
#include <string.h>

int
main ()
{
  int major, minor, micro;
  char *tmp_version;
  FILE *errorlog;

  if ((errorlog = fopen("]ERRORLOG[", "w")) == NULL) {
     exit(1);
   }

  system ("touch ]RUNLOG[");

  /* HP/UX 9 (%@#!) writes to sscanf strings */
  tmp_version = strdup("$]LDOWN[_min_version");
  if (!tmp_version) {
     exit(1);
   }
  if (sscanf(tmp_version, "%d.%d.%d", &major, &minor, &micro) != 3) {
     fprintf(errorlog, "*** %s: bad version string\n", "$]LDOWN[_min_version");
     exit(1);
   }

  if ((]MAJOR[ != $]LDOWN[_config_major_version) ||
      (]MINOR[ != $]LDOWN[_config_minor_version) ||
      (]MICRO[ != $]LDOWN[_config_micro_version))
    {
      fprintf(errorlog, "*** '$]UP[_CONFIG ]LIBCONFIG_VERSION[' returned %d.%d.%d, but \n", \
        $]LDOWN[_config_major_version, $]LDOWN[_config_minor_version, \
        $]LDOWN[_config_micro_version);
      fprintf(errorlog, "*** ]UP[ (%d.%d.%d) was found!\n", \
        ]MAJOR[, ]MINOR[, ]MICRO[);
      fprintf(errorlog, "***\n");
      fprintf(errorlog, "*** If $]LDOWN[_config was correct, then it is best to remove\n");
      fprintf(errorlog, "*** the old version of ]UP[.  You may also be able to\n");
      fprintf(errorlog, "*** fix the error by modifying your LD_LIBRARY_PATH enviroment\n");
      fprintf(errorlog, "*** variable, or by editing /etc/ld.so.conf.  Make sure you have\n");
      fprintf(errorlog, "*** run ldconfig if that is required on your system.\n");
      fprintf(errorlog, "*** If $]LDOWN[_config was wrong, set the environment\n");
      fprintf(errorlog, "*** variable ]UP[_CONFIG to point to the correct copy of\n");
      fprintf(errorlog, "*** $]LDOWN[_config, and remove the file config.cache\n");
      fprintf(errorlog, "*** before re-running configure.\n");
    }
#if defined (]DEFMAJOR[) && defined (]DEFMINOR[) && defined (]DEFMICRO[)
  else if ((]MAJOR[ != ]DEFMAJOR[) ||
           (]MINOR[ != ]DEFMINOR[) ||
           (]MICRO[ != ]DEFMICRO[))
    {
      fprintf(errorlog, "*** ]UP[ header files (version %d.%d.%d) do not match\n",
             ]DEFMAJOR[, ]DEFMINOR[, ]DEFMICRO[);
      fprintf(errorlog, "*** library (version %d.%d.%d)\n",
             ]MAJOR[, ]MINOR[, ]MICRO[);
    }
#endif /* defined (]DEFMAJOR[) ... */
  else
    {
      if ((]MAJOR[ > major) ||
        ((]MAJOR[ == major) && (]MINOR[  > minor)) ||
        ((]MAJOR[ == major) && (]MINOR[ == minor) && (]MICRO[ >= micro)))
      {
        return 0;
       }
     else
      {
        fprintf(errorlog, "*** An old version of ]UP[ (%d.%d.%d) was found.\n",
               ]MAJOR[, ]MINOR[, ]MICRO[);
        fprintf(errorlog, "*** You need a version of ]UP[ newer than %d.%d.%d.\n",
               major, minor, micro);
        /*fprintf(errorlog, "*** The latest version of ]UP[ is always available from ftp://ftp.my.site\n");*/
        fprintf(errorlog, "***\n");
        fprintf(errorlog, "*** If you have already installed a sufficiently new version, this\n");
        fprintf(errorlog, "*** error probably means that the wrong copy of the $]LDOWN[_config\n");
        fprintf(errorlog, "*** shell script is being found.  The easiest way to fix this is to\n");
        fprintf(errorlog, "*** remove the old version of ]UP[, but you can also set the\n");
        fprintf(errorlog, "*** ]UP[_CONFIG environment variable to point to the correct\n");
        fprintf(errorlog, "*** copy of $]LDOWN[_config.  (In this case, you will have to\n");
        fprintf(errorlog, "*** modify your LD_LIBRARY_PATH environment variable, or edit\n");
        fprintf(errorlog, "*** /etc/ld.so.conf so that the correct libraries are found at\n");
        fprintf(errorlog, "*** run-time.)\n");
      }
    }
  return 1;
}
],, [CACHE[]_present="no"],
    [AC_PATH_LIB_ERROR([cross compiling; assumed OK.])])
  CFLAGS="$ac_save_CFLAGS"
  LIBS="$ac_save_LIBS"

if test -f RUNLOG ; then
  :
elif test x$LDOWN[]_version_test_enabled = xyes ; then
  AC_PATH_LIB_ERROR([Could not run UP test program, checking why...])
  AC_PATH_LIB_ERROR
  _AC_PATH_LIB_CHECK_LINK(dnl
    [AC_PATH_LIB_ERROR([The test program compiled, but did not run.  This usually])
     AC_PATH_LIB_ERROR([means that the run-time linker is not finding UP or])
     AC_PATH_LIB_ERROR([finding the wrong version of UP.  If it is not finding])
     AC_PATH_LIB_ERROR([UP, you will need to set your LD_LIBRARY_PATH environment])
     AC_PATH_LIB_ERROR([variable, or edit /etc/ld.so.conf to point to the installed])
     AC_PATH_LIB_ERROR([location.  Also, make sure you have run ldconfig if that is])
     AC_PATH_LIB_ERROR([required on your system.])
     AC_PATH_LIB_ERROR
     AC_PATH_LIB_ERROR([If you have an old version installed, it is best to remove])
     AC_PATH_LIB_ERROR([it, although you may also be able to get things to work by])
     AC_PATH_LIB_ERROR([modifying LD_LIBRARY_PATH])
    ],
    [AC_PATH_LIB_ERROR([The test program failed to compile or link.  See the file])
     AC_PATH_LIB_ERROR([config.log for the exact error that occured.  This usually])
     AC_PATH_LIB_ERROR([means UP was incorrectly installed or that you have])
     AC_PATH_LIB_ERROR([moved UP since it was installed.  In the latter case,])
     AC_PATH_LIB_ERROR([you may want to edit the $LDOWN[]_config script:])
     AC_PATH_LIB_ERROR([$UP[]_CONFIG])
    ])
fi
rm -f RUNLOG
m4_popdef([RUNLOG])dnl
m4_popdef([MAJOR])dnl
m4_popdef([MINOR])dnl
m4_popdef([MICRO])dnl
m4_popdef([DEFMAJOR])dnl
m4_popdef([DEFMINOR])dnl
m4_popdef([DEFMICRO])dnl
])# _AC_PATH_LIB_CHECK_TEST_COMPILE_DEFAULT


# _AC_PATH_LIB_CHECK_VERSION_DEFAULT
# ----------------------------------
# Check that the library version (config) is greater than or equal to
# the requested (minimum) version.
AC_DEFUN([_AC_PATH_LIB_CHECK_VERSION],
[m4_if([$2], , ,
       [if test x$LDOWN[]_present_avoidcache = xyes ; then
         if test \
             "$LDOWN[]_config_major_version" -lt "$LDOWN[]_min_major_version" -o \
             "$LDOWN[]_config_major_version" -eq "$LDOWN[]_min_major_version" -a \
             "$LDOWN[]_config_minor_version" -lt "$LDOWN[]_min_minor_version" -o \
             "$LDOWN[]_config_major_version" -eq "$LDOWN[]_min_major_version" -a \
             "$LDOWN[]_config_minor_version" -eq "$LDOWN[]_min_minor_version" -a \
             "$LDOWN[]_config_micro_version" -lt "$LDOWN[]_min_micro_version" ; then
           CACHE[]_present="no"
           LDOWN[]_version_test_error="yes"
           AC_PATH_LIB_ERROR([$UP[]_CONFIG --version' returned $LDOWN[]_config_major_version.$LDOWN[]_config_minor_version.$LDOWN[]_config_micro_version, but])
           AC_PATH_LIB_ERROR([UP (>= $LDOWN[]_min_version) was needed.])
           AC_PATH_LIB_ERROR
           AC_PATH_LIB_ERROR([If $]LDOWN[_config was wrong, set the environment])
           AC_PATH_LIB_ERROR([variable ]UP[_CONFIG to point to the correct copy of])
           AC_PATH_LIB_ERROR([$]LDOWN[_config, and remove the file config.cache])
           AC_PATH_LIB_ERROR([before re-running configure.])
         else
           CACHE[]_present="yes"
         fi
       fi])
])# _AC_PATH_LIB_CHECK_VERSION_DEFAULT


# _AC_PATH_LIB_CHECK_LINK_DEFAULT(SUCCESS, FAIL)
# ----------------------------------------------
# Check if the library will link successfully.  If specified, run
# SUCCESS or FAIL on success or failure
AC_DEFUN([_AC_PATH_LIB_CHECK_LINK],
[ac_save_CFLAGS="$CFLAGS"
ac_save_LIBS="$LIBS"
CFLAGS="$CFLAGS $UP[]_CFLAGS"
LIBS="$LIBS $UP[]_LIBS"
AC_TRY_LINK([ #include <stdio.h> ], ,
            [m4_if([$1], , :, [$1])],
            [m4_if([$2], , :, [$2])])
CFLAGS="$ac_save_CFLAGS"
LIBS="$ac_save_LIBS"
])# _AC_PATH_LIB_CHECK_LINK_DEFAULT




## ------------------- ##
## 4. Error reporting. ##
## ------------------- ##


# AC_PATH_LIB_ERROR(MESSAGE)
# --------------------------
# Print an error message, MESSAGE, to the error log.
AC_DEFUN([AC_PATH_LIB_ERROR],
[echo '*** m4_if([$1], , , [$1])' >>ERRORLOG])


# _AC_PATH_LIB_ERROR_DUMP
# -----------------------
# Print the error log (after main AC_CACHE_CHECK completes).
AC_DEFUN([_AC_PATH_LIB_ERROR_DUMP],
[if test -f ERRORLOG ; then
  cat ERRORLOG
  rm -f ERRORLOG
fi])




## ------------------ ##
## 5. Feature macros. ##
## ------------------ ##


# AC_PATH_LIB_PKGCONFIG
# ---------------------
# Enable pkgconfig support in libconfig script (default).
AC_DEFUN([AC_PATH_LIB_PKGCONFIG],
[m4_define([AC_PATH_LIB_USEPKGCONFIG], [true])
])dnl


# AC_PATH_LIB_LIBCONFIG
# ---------------------
# Disable pkgconfig support in libconfig script.
AC_DEFUN([AC_PATH_LIB_LIBCONFIG],
[m4_define([AC_PATH_LIB_USEPKGCONFIG], [false])
])dnl


# AC_PATH_LIB_REGISTER (MACRO, REPLACEMENT)
# -----------------------------------------
# Register a macro to replace the default checks.  Use the REPLACEMENT
# macro for the check macro MACRO.
#
# Possible MACROs are:
#   _AC_PATH_LIB_CHECK_COMPILE and
#   _AC_PATH_LIB_CHECK_VERSION
# You should make sure that replacement macros use the same arguments
# (if any), and do error logging in the same manner and behave in the
# same way as the original.

# Non-default header names may be specified, as well as version
# variable names in the library itself (needed for
# _AC_PATH_LIB_CHECK_COMPILE):
#   _AC_PATH_LIB_HEADER
#   _AC_PATH_LIB_VERSION_PREFIX (default library_)
#   _AC_PATH_LIB_VERSION_MAJOR (default major)
#   _AC_PATH_LIB_VERSION_MINOR (default minor)
#   _AC_PATH_LIB_VERSION_MICRO (default micro)
#   _AC_PATH_LIB_VERSION_SUFFIX (default _version)
#   _AC_PATH_LIB_DEFVERSION_PREFIX (default LIBRARY_)
#   _AC_PATH_LIB_DEFVERSION_MAJOR (default MAJOR)
#   _AC_PATH_LIB_DEFVERSION_MINOR (default MINOR)
#   _AC_PATH_LIB_DEFVERSION_MICRO (default MICRO)
#   _AC_PATH_LIB_DEFVERSION_SUFFIX (default _VERSION)
# For example, library_major_version.
AC_DEFUN([AC_PATH_LIB_REGISTER],
[m4_define([$1], [$2])])


# AC_PATH_LIB_CHECK_REGISTER_DEFAULTS
# -----------------------------------
# Restore the default check macros.
AC_DEFUN([AC_PATH_LIB_CHECK_REGISTER_DEFAULTS],
[_AC_PATH_LIB_CHECK_REGISTER_DEFAULTS([_AC_PATH_LIB_CHECK_COMPILE],
                                       [_AC_PATH_LIB_CHECK_VERSION],
                                       [_AC_PATH_LIB_HEADER],
                                       [_AC_PATH_LIB_VERSION_PREFIX],
                                       [_AC_PATH_LIB_VERSION_MAJOR],
                                       [_AC_PATH_LIB_VERSION_MINOR],
                                       [_AC_PATH_LIB_VERSION_MICRO],
                                       [_AC_PATH_LIB_VERSION_SUFFIX],
                                       [_AC_PATH_LIB_DEFVERSION_PREFIX],
                                       [_AC_PATH_LIB_DEFVERSION_MAJOR],
                                       [_AC_PATH_LIB_DEFVERSION_MINOR],
                                       [_AC_PATH_LIB_DEFVERSION_MICRO],
                                       [_AC_PATH_LIB_DEFVERSION_SUFFIX])
])# AC_PATH_LIB_CHECK_REGISTER_DEFAULTS


# _AC_PATH_LIB_CHECK_REGISTER_DEFAULTS(MACROs ...)
# ------------------------------------------------
# Undefine MACROs.
AC_DEFUN([AC_PATH_LIB_CHECK_REGISTER_DEFAULTS],
[m4_if([$1], , ,
       [m4_ifdef([$1],
                 [m4_undefine([$1])])
        AC_PATH_LIB_CHECK_REGISTER_DEFAULTS(m4_shift($@))
       ])
])