#							-*- Autotest -*-

AT_BANNER([Semantics.])

# Copyright (C) 2000-2002, 2004-2007, 2009-2012 Free Software
# Foundation, Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


## -------------------------------- ##
## Members of the AC_CHECK family.  ##
## -------------------------------- ##


# AC_CHECK_LIB
# ------------
# Well, I can't imagine a system where `cos' is neither in libc, nor
# in libm.  Nor can I imagine a lib more likely to exists than libm.
# But there are systems without libm, on which we don't want to have
# this test fail, so exit successfully if `cos' is in libc.
AT_CHECK_MACRO([AC_CHECK_LIB],
[AC_TRY_LINK_FUNC(cos,
		  [AC_MSG_ERROR([`cos' is in `libc'], 77)])

AC_CHECK_LIB(m, cos,,
	     [AC_MSG_ERROR([cannot find `cos' in `libm'])])

# No kidding, using variables was broken in 2.50 :(
ac_sin=sin
AC_CHECK_LIB(m, $ac_sin,,
      [AC_MSG_ERROR([cannot find `\$ac_sin' (= `$ac_sin') in `libm'])])

ac_m=m
AC_CHECK_LIB($ac_m, acos,,
      [AC_MSG_ERROR([cannot find `acos' in `\$ac_m' (= `$ac_m')])])

ac_asin=asin
AC_CHECK_LIB($ac_m, $ac_asin,,
      [AC_MSG_ERROR([cannot find `\$ac_asin' (= `$ac_asin') in `\$ac_m' (= `$ac_m')])])

# But if the bug is in the caching mechanism, then be sure we
# correctly detect failures.

AC_CHECK_LIB(m, cossack,
	     [AC_MSG_ERROR([found `cossack' in `libm'])])

# No kidding, using variables was broken in 2.50 :(
ac_sinner=sinner
AC_CHECK_LIB(m, $ac_sinner,
      [AC_MSG_ERROR([found `\$ac_sinner' (= `$ac_sinner') in `libm'])])

ac_m=m
AC_CHECK_LIB($ac_m, acossack,
      [AC_MSG_ERROR([found `acossack' in `\$ac_m' (= `$ac_m')])])

ac_asinner=asinner
AC_CHECK_LIB($ac_m, $ac_asinner,
      [AC_MSG_ERROR([found `\$ac_asinner' (= `$ac_asinner') in `\$ac_m' (= `$ac_m')])])

])


# AC_SEARCH_LIBS
# --------------
AT_CHECK_MACRO([AC_SEARCH_LIBS],
[
AC_SEARCH_LIBS(cos, oser m ust,,
	     [AC_MSG_ERROR([cannot find `cos'])])

case "$ac_cv_search_cos" in
  -loser|-lust) AC_MSG_ERROR([jeez, $ac_cv_search_cos must be a cool library!]) ;;
esac
])


# AC_SEARCH_LIBS (none needed)
# ----------------------------
AT_CHECK_MACRO([AC_SEARCH_LIBS (none needed)],
[
AC_SEARCH_LIBS(printf, oser c ust,,
	     [AC_MSG_ERROR([cannot find `printf'])])

case "$ac_cv_search_printf" in
  -loser|-lust) AC_MSG_ERROR([jeez, $ac_cv_search_printf must be a cool library!]) ;;
  -lc) AC_MSG_ERROR([huh, you need to give -lc?])
esac
])


# AC_CHECK_DECLS
# --------------
# Check that it performs the correct actions:
AT_CHECK_MACRO([AC_CHECK_DECLS],
[[AC_CHECK_DECLS([yes, no, myenum, mystruct, myfunc, mymacro1, mymacro2],,,
		 [[int yes = 1;
		   enum { myenum };
		   struct { int x[20]; } mystruct;
		   extern int myfunc();
		   #define mymacro1(arg) arg
		   #define mymacro2]])
  # The difference in space-before-open-paren is intentional.
  AC_CHECK_DECLS([basenam (char *), dirnam(char *),
		  [moreargs (char, short, int, long, void *, char [], float, double)]],,,
		 [[#ifdef __cplusplus
		   extern "C++" char *basenam (char *);
		   extern "C++" const char *basenam (const char *);
		   #else
		   extern char *basenam (const char *);
		   #endif
		   #ifdef __cplusplus
		   extern "C" {
		   #endif
		   extern int moreargs (char, short, int, long, void *,
					char [], float, double);
		   #ifdef __cplusplus
		   }
		   #endif
		   ]])
  AC_CHECK_DECL([declared (char *)],, [AS_EXIT([1])],
		[[#ifdef __cplusplus
		  extern "C++" char *declared (char *);
		  extern "C++" const char *declared (const char *);
		  #else
		  extern char *declared (const char *);
		  #endif
		]])
  AC_CHECK_DECL([undeclared (char *)], [AS_EXIT([1])],, [[]])
]],
[AT_CHECK_DEFINES(
[#define HAVE_DECL_BASENAM 1
#define HAVE_DECL_DIRNAM 0
#define HAVE_DECL_MOREARGS 1
#define HAVE_DECL_MYENUM 1
#define HAVE_DECL_MYFUNC 1
#define HAVE_DECL_MYMACRO1 1
#define HAVE_DECL_MYMACRO2 1
#define HAVE_DECL_MYSTRUCT 1
#define HAVE_DECL_NO 0
#define HAVE_DECL_YES 1
])])


# AC_CHECK_FUNCS
# --------------
# Check that it performs the correct actions:
# Must define HAVE_PRINTF, but not HAVE_AUTOCONF_FTNIRP
AT_CHECK_MACRO([AC_CHECK_FUNCS],
[AC_CHECK_FUNCS(printf autoconf_ftnirp)],
[AT_CHECK_DEFINES(
[/* #undef HAVE_AUTOCONF_FTNIRP */
#define HAVE_PRINTF 1
])])


# AC_REPLACE_FUNCS
# ----------------
# Check that it performs the correct actions: autoconf_ftnirp.c must
# be compiled, and must define HAVE_PRINTF, but not HAVE_AUTOCONF_FTNIRP
# FIXME: Maybe check the traces?
AT_SETUP([AC_REPLACE_FUNCS])

AT_DATA([config.in],
[@LIBOBJS@
])

AT_CONFIGURE_AC(
[AC_CONFIG_FILES([config.libobjs:config.in])
AC_REPLACE_FUNCS([printf \
autoconf_ftnirp])
funcs='fprintf fopen autoconf_ftnirpf'
AH_TEMPLATE([HAVE_FOPEN], [])
AH_TEMPLATE([HAVE_FPRINTF], [])
AH_TEMPLATE([HAVE_AUTOCONF_FTNIRPF], [])
AC_REPLACE_FUNCS([\
$funcs])
AS_UNSET([funcs])])

AT_CHECK_AUTOCONF([-W obsolete])
AT_CHECK_AUTOHEADER
AT_CHECK_CONFIGURE
AT_CHECK_ENV
AT_CHECK_DEFINES(
[/* #undef HAVE_AUTOCONF_FTNIRP */
/* #undef HAVE_AUTOCONF_FTNIRPF */
#define HAVE_FOPEN 1
#define HAVE_FPRINTF 1
#define HAVE_PRINTF 1
])

AT_CHECK([sed 's/  */ /g;s/^ //;s/ $//' config.libobjs], [],
	 [${LIBOBJDIR}autoconf_ftnirp$U.o ${LIBOBJDIR}autoconf_ftnirpf$U.o
])

AT_CLEANUP


# AC_CHECK_HEADERS
# ----------------
# Check that it performs the correct actions:
# Must define HAVE_STDIO_H, but not HAVE_AUTOCONF_IO_H.
AT_SETUP([AC_CHECK_HEADERS])

AT_DATA([autoconf_io.h],
[blah blah
])

AT_CONFIGURE_AC([AC_CHECK_HEADERS(stdio.h autoconf_io.h)])
AT_CHECK_AUTOCONF([-W obsolete])
AT_CHECK_AUTOHEADER
AT_CHECK_CONFIGURE([CPPFLAGS=-I.], [0], [ignore],
[configure: WARNING: autoconf_io.h: present but cannot be compiled
configure: WARNING: autoconf_io.h:     check for missing prerequisite headers?
configure: WARNING: autoconf_io.h: see the Autoconf documentation
configure: WARNING: autoconf_io.h:     section "Present But Cannot Be Compiled"
configure: WARNING: autoconf_io.h: proceeding with the compiler's result
])
AT_CHECK_ENV
AT_CHECK_DEFINES(
[/* #undef HAVE_AUTOCONF_IO_H */
#define HAVE_STDIO_H 1
])

AT_CLEANUP


# AC_CHECK_HEADERS_OLD
# --------------------
# Check that it performs the correct actions:
# Must not check prerequisites, hence define header2.h
AT_SETUP([AC_CHECK_HEADERS (preprocessor test)])

AT_DATA([header1.h],
[typedef int foo;
])

AT_DATA([header2.h],
[typedef foo bar;
])

AT_CONFIGURE_AC([AC_CHECK_HEADERS(header2.h, [], [], -)])

AT_CHECK_AUTOCONF([-W obsolete])
AT_CHECK_AUTOHEADER
AT_CHECK_CONFIGURE([CPPFLAGS=-I.])
AT_CHECK_ENV
AT_CHECK_DEFINES(
[#define HAVE_HEADER2_H 1
])

AT_CLEANUP


# AC_CHECK_HEADERS_NEW
# --------------------
# Check that it performs the correct actions:
# Must check prerequisites, hence define header2.h but not header3.h
AT_SETUP([AC_CHECK_HEADERS (compiler test)])

AT_DATA([header1.h],
[typedef int foo;
])

AT_DATA([header2.h],
[typedef foo bar;
])

AT_DATA([header3.h],
[typedef bar wow;
])

AT_CONFIGURE_AC(
[AC_CHECK_HEADERS(header2.h header3.h, [], [], [[@%:@include "header1.h"]])])

AT_CHECK_AUTOCONF([-W obsolete])
AT_CHECK_AUTOHEADER
AT_CHECK_CONFIGURE([CPPFLAGS=-I.])
AT_CHECK_ENV
AT_CHECK_DEFINES(
[#define HAVE_HEADER2_H 1
/* #undef HAVE_HEADER3_H */
])

AT_CLEANUP


# AC_CHECK_MEMBER
# ---------------
# Check that it performs the correct actions.
# Must define HAVE_STRUCT_YES_S_YES, but not HAVE_STRUCT_YES_S_NO.
AT_CHECK_MACRO([AC_CHECK_MEMBER],
[[AC_CHECK_MEMBER([struct yes_s.yes],
		  [AC_DEFINE([HAVE_STRUCT_YES_S_YES], [1],
			     [Define to 1 if `yes' is a member of `struct yes_s'.])],,
		   [struct sub { int x; };
		    struct yes_s { int yes; struct sub substruct; };])
  AC_CHECK_MEMBER([struct yes_s.no],
		  [AC_DEFINE([HAVE_STRUCT_YES_S_NO], [1],
			     [Define to 1 if `no' is a member of `struct yes_s'.])],,
		   [struct sub { int x; };
		    struct yes_s { int yes; struct sub substruct; };])
  AC_CHECK_MEMBER([struct yes_s.substruct],
		  [AC_DEFINE([HAVE_STRUCT_YES_S_SUBSTRUCT], [1],
			     [Define to 1 if `substruct' is a member of `struct yes_s'.])],,
		   [struct sub { int x; };
		    struct yes_s { int yes; struct sub substruct; };])]],
[AT_CHECK_DEFINES(
[/* #undef HAVE_STRUCT_YES_S_NO */
#define HAVE_STRUCT_YES_S_SUBSTRUCT 1
#define HAVE_STRUCT_YES_S_YES 1
])])

# AC_CHECK_MEMBERS
# ----------------
# Check that it performs the correct actions.
# Must define HAVE_STRUCT_YES_S_YES, but not HAVE_STRUCT_YES_S_NO.
AT_CHECK_MACRO([AC_CHECK_MEMBERS],
[[AC_CHECK_MEMBERS([struct yes_s.yes, struct yes_s.no, struct yes_s.substruct],,,
		   [struct sub { int x; };
		    struct yes_s { int yes; struct sub substruct; };])]],
[AT_CHECK_DEFINES(
[/* #undef HAVE_STRUCT_YES_S_NO */
#define HAVE_STRUCT_YES_S_SUBSTRUCT 1
#define HAVE_STRUCT_YES_S_YES 1
])
AT_CHECK([grep 'yes.*member of.*yes_s' config.h], [], [ignore])
])


# AC_CHECK_ALIGNOF
# ----------------
AT_CHECK_MACRO_CROSS([AC_CHECK_ALIGNOF],
[[AC_CHECK_ALIGNOF(char)
AC_CHECK_ALIGNOF(charchar,
[[#include <stddef.h>
#include <stdio.h>
typedef char charchar[2];]])
AC_CHECK_ALIGNOF(charcharchar)
]],
[AT_CHECK_DEFINES(
[#define ALIGNOF_CHAR 1
#define ALIGNOF_CHARCHAR 1
#define ALIGNOF_CHARCHARCHAR 0
])])


# AC_CHECK_ALIGNOF struct
# -----------------------
AT_CHECK_MACRO_CROSS([AC_CHECK_ALIGNOF struct],
[[AC_CHECK_ALIGNOF([struct { char c; }])
AC_CHECK_ALIGNOF([struct nosuchstruct])
]],
[AT_CHECK([[grep "#define ALIGNOF_STRUCT___CHAR_C___ [1-9]" config.h]],
	 0, ignore)
AT_CHECK([[grep "#define ALIGNOF_STRUCT_NOSUCHSTRUCT 0" config.h]],
	 0, ignore)
])

# AC_CHECK_SIZEOF
# ---------------
AT_CHECK_MACRO_CROSS([AC_CHECK_SIZEOF],
[[AC_CHECK_SIZEOF(char)
AC_CHECK_SIZEOF(charchar,,
[[#include <stdio.h>
typedef char charchar[2];]])
AC_CHECK_SIZEOF(charcharchar)
]],
[AT_CHECK_DEFINES(
[#define SIZEOF_CHAR 1
#define SIZEOF_CHARCHAR 2
#define SIZEOF_CHARCHARCHAR 0
])])


# AC_CHECK_SIZEOF struct
# ----------------------
AT_CHECK_MACRO_CROSS([AC_CHECK_SIZEOF struct],
[[AC_C_CONST
AC_CHECK_SIZEOF([struct x], [], [struct x { char c; int x; };])
AC_CHECK_SIZEOF([const struct x], [], [struct x { const char *p; int x; };])
AC_CHECK_SIZEOF([struct nosuchstruct])
# Taken from autoconf.texi:Generic Compiler Characteristics.
AC_CHECK_SIZEOF([int *])
]],
[AT_CHECK([[grep "#define SIZEOF_STRUCT_X [1-9]" config.h]],
	 0, ignore)
AT_CHECK([[grep "#define SIZEOF_CONST_STRUCT_X [1-9]" config.h]],
	 0, ignore)
AT_CHECK([[grep "#define SIZEOF_STRUCT_NOSUCHSTRUCT 0" config.h]],
	 0, ignore)
AT_CHECK([[grep "#define SIZEOF_INT_P [1-9]" config.h]],
	 0, ignore)
])


# AC_CHECK_TYPES
# --------------
# Check that it performs the correct actions.
# Must define HAVE_STRUCT_YES_S, HAVE_INT, but not HAVE_STRUCT_NO_S.
# `int' and `struct yes_s' are both checked to test both the compiler
# builtin types, and defined types.
AT_CHECK_MACRO([AC_CHECK_TYPES],
[[AC_CHECK_TYPES([int, struct yes_s, struct no_s],,,
		 [struct yes_s { int yes ;} ;])]],
[AT_CHECK_DEFINES(
[#define HAVE_INT 1
/* #undef HAVE_STRUCT_NO_S */
#define HAVE_STRUCT_YES_S 1
])])


# AC_CHECK_TYPES
# --------------
# Check that we properly dispatch properly to the old implementation
# or to the new one.
AT_SETUP([AC_CHECK_TYPES: backward compatibility])

AT_DATA([configure.ac],
[[AC_INIT
define([_AC_CHECK_TYPE_NEW], [NEW])
define([_AC_CHECK_TYPE_OLD], [OLD])
#(cut-from-here
AC_CHECK_TYPE(ptrdiff_t)
AC_CHECK_TYPE(ptrdiff_t, int)
AC_CHECK_TYPE(quad, long long int)
AC_CHECK_TYPE(table_42, [int[42]])
# Nice machine!
AC_CHECK_TYPE(uint8_t, uint65536_t)
AC_CHECK_TYPE(a,b,c,d)
#to-here)
AC_OUTPUT
]])

AT_CHECK_AUTOCONF
AT_CHECK([[sed -e '/^#(cut-from-here/,/^#to-here)/!d' -e '/^#/d' configure]],
	 0,
	 [NEW
OLD
OLD
OLD
OLD
NEW
])

AT_CLEANUP


# AC_CHECK_FILES
# --------------
# FIXME: To really test HAVE_AC_EXISTS2 and HAVE_AC_MISSING2 we need to
# open AH_TEMPLATE to `configure.ac', which is not yet the case.
AT_CHECK_MACRO([AC_CHECK_FILES],
[touch at-exists1 at-exists2
ac_exists2=at-exists2
ac_missing2=at-missing2
AC_CHECK_FILES(at-exists1 at-missing1 $ac_exists2 $ac_missing2)
rm at-exists1 at-exists2],
[AT_CHECK_DEFINES(
[#define HAVE_AT_EXISTS1 1
/* #undef HAVE_AT_MISSING1 */
])])



## ------------------------------ ##
## AC_CHECK_PROG & AC_PATH_PROG.  ##
## ------------------------------ ##


# AT_CHECK_PROGS_PREPARE
# ----------------------
# Create a sub directory `path' with 6 subdirs which all 7 contain
# an executable `tool'. `6' contains a `better' tool.
m4_define([AT_CHECK_PROGS_PREPARE],
[mkdir path

cat >path/tool <<\EOF
#! /bin/sh
exit 0
EOF
chmod +x path/tool

for i in 1 2 3 4 5 6
do
  mkdir path/$i
  cp path/tool path/$i
done
cp path/tool path/6/better])


# -------------------------------- #
# AC_CHECK_PROG & AC_CHECK_PROGS.  #
# -------------------------------- #

AT_SETUP([AC_CHECK_PROG & AC_CHECK_PROGS])

AT_CHECK_PROGS_PREPARE

AT_DATA([configure.ac],
[[AC_INIT
pwd=`pwd`
p="1${PATH_SEPARATOR}2${PATH_SEPARATOR}3${PATH_SEPARATOR}4${PATH_SEPARATOR}5${PATH_SEPARATOR}6"
path=`echo $p | sed -e 's,\([[0-9]]\),'"$pwd"'/path/\1,g'`
fail=false

AC_CHECK_PROG(TOOL1, tool, found, not-found, $path)
test "$TOOL1" = found || fail=:

# Yes, the semantics of this macro is weird.
AC_CHECK_PROG(TOOL2, tool,, not-found, $path)
test "$TOOL2" = not-found || fail=:

AC_CHECK_PROG(TOOL3, tool, tool, not-found, $path, $pwd/path/1/tool)
test "$TOOL3" = "$pwd/path/2/tool" || fail=:

AC_CHECK_PROG(TOOL4, better, better, not-found, $path, $pwd/path/1/tool)
test "$TOOL4" = better || fail=:

# When a tool is not found, and no value is given for not-found,
# the variable is left empty.
AC_CHECK_PROGS(TOOL5, missing,, $path)
test -z "$TOOL5" || fail=:

AC_CHECK_PROGS(TOOL6, missing tool better,, $path)
test "$TOOL6" = tool || fail=:

# No AC-OUTPUT, we don't need config.status.
$fail &&
  AC_MSG_ERROR([[CHECK_PROG failed]])
AS_EXIT(0)
]])

AT_CHECK_AUTOCONF
AT_CHECK_CONFIGURE

AT_CLEANUP



## ---------------- ##
## AC_C_BIGENDIAN.  ##
## ---------------- ##

AT_SETUP([AC_C_BIGENDIAN])
AT_KEYWORDS([cross])

# Make sure that AC_C_BIGENDIAN behave the same whether we are
# cross-compiling or not.

_AT_CHECK_AC_MACRO(
  [[AC_C_BIGENDIAN(
      [ac_endian=big],
      [ac_endian=little],
      [ac_endian=unknown],
      [ac_endian=universal])
   echo $ac_endian > at-endian
]])

rm -f config.hin  # So that next run of autoheader is quiet.
_AT_CHECK_AC_MACRO(
  [[# Force cross compiling.
   cross_compiling=yes
   ac_tool_warned=yes
   AC_C_BIGENDIAN(
     [ac_endian=big],
     [ac_endian=little],
     [ac_endian=unknown],
     [ac_endian=universal])
   ac_prevendian=`cat at-endian`
   # Check that we have found the same result as in the previous run
   # or unknown (because the cross-compiling check is allowed to fail;
   # although it might be interesting to suppress this comparison, just
   # to know on which system it fails if it ever does).
   if test $ac_endian != $ac_prevendian && test $ac_endian != unknown; then
     AC_MSG_ERROR([unexpected endianness: first run found '$ac_prevendian' but second run found '$ac_endian'])
   fi
]])

# Make sure AC_C_BIGENDIAN with no argument will create a config.h template
# containing "WORDS_BIGENDIAN".
AT_CONFIGURE_AC([[AC_C_BIGENDIAN]])
# --force is necessary, the computer might be too fast.
AT_CHECK_AUTOHEADER([--force])
AT_CHECK([grep WORDS_BIGENDIAN config.hin], [], [ignore])

AT_CLEANUP


# ------------------------------ #
# AC_PATH_PROG & AC_PATH_PROGS.  #
# ------------------------------ #

AT_SETUP([AC_PATH_PROG & AC_PATH_PROGS])

AT_CHECK_PROGS_PREPARE

AT_DATA([configure.ac],
[[AC_INIT
pwd=`pwd`
p="1${PATH_SEPARATOR}2${PATH_SEPARATOR}3${PATH_SEPARATOR}4${PATH_SEPARATOR}5${PATH_SEPARATOR}6"
path=`echo $p | sed -e 's,\([[0-9]]\),'"$pwd"'/path/\1,g'`
fail=false

AC_PATH_PROG(TOOL1, tool, not-found, $path)
test "$TOOL1" = "$pwd/path/1/tool" || fail=:

AC_PATH_PROG(TOOL2, better, not-found, $path)
test "$TOOL2" = "$pwd/path/6/better" || fail=:

# When a tool is not found, and no value is given for not-found,
# the variable is left empty.
AC_PATH_PROGS(TOOL3, missing,, $path)
test -z "$TOOL3" || fail=:

AC_PATH_PROGS(TOOL4, missing tool better,, $path)
test "$TOOL4" = "$pwd/path/1/tool" || fail=:

# No AC-OUTPUT, we don't need config.status.
$fail &&
  AC_MSG_ERROR([[PATH_PROG failed]])
AS_EXIT(0)
]])

AT_CHECK_AUTOCONF
AT_CHECK_CONFIGURE

AT_CLEANUP



# ----------------------------- #
# AC_PATH_PROGS_FEATURE_CHECK.  #
# ----------------------------- #

AT_SETUP([AC_PATH_PROGS_FEATURE_CHECK])

# This test doesn't work if `pwd` contains white space
case `pwd` in
  *\ * | *\	*) AT_CHECK([exit 77]) ;;
esac

AT_CHECK_PROGS_PREPARE

AT_DATA([configure.ac],
[[AC_INIT
pwd=`pwd`
p="1${PATH_SEPARATOR}2${PATH_SEPARATOR}3${PATH_SEPARATOR}4${PATH_SEPARATOR}5${PATH_SEPARATOR}6"
path=`echo $p | sed -e 's,\([[0-9]]\),'"$pwd"'/path/\1,g'`
fail=false

# Find first candidate and stop search
AC_PATH_PROGS_FEATURE_CHECK(TOOL1, [tool better],
  [$ac_path_TOOL1 && ac_cv_path_TOOL1=$ac_path_TOOL1 ac_path_TOOL1_found=:],
  fail=:, $path)
test -z "$TOOL1" || fail=:
test "$ac_cv_path_TOOL1" = "$pwd/path/1/tool" || fail=:

# Keep searching each candidate
AC_PATH_PROGS_FEATURE_CHECK(TOOL2, [tool better],
  [$ac_path_TOOL2 && ac_cv_path_TOOL2=$ac_path_TOOL2],
  fail=:, $path)
test "$ac_cv_path_TOOL2" = "$pwd/path/6/better" || fail=:

# Only accept better candidate
AC_PATH_PROGS_FEATURE_CHECK(TOOL3, [tool better],
  [case "$ac_path_TOOL3" in #(
    *better) ac_cv_path_TOOL3=$ac_path_TOOL3;;
  esac],
  fail=:, $path)
test "$ac_cv_path_TOOL3" = "$pwd/path/6/better" || fail=:

# When a tool is not found, and no action is given for not-found,
# the variable is left empty.
AC_PATH_PROGS_FEATURE_CHECK(TOOL4, missing,
  [ac_cv_path_TOOL4=$ac_path_TOOL4], [], $path)
test -z "$ac_cv_path_TOOL4" || fail=:

# Test action when tool is not found
AC_PATH_PROGS_FEATURE_CHECK(TOOL5, missing, [],
  [ac_cv_path_TOOL5='not found'], $path)
test "$ac_cv_path_TOOL5" = "not found" || fail=:

# Test that pre-set tool bypasses feature test
TOOL6=$pwd/path/6/better
AC_PATH_PROGS_FEATURE_CHECK(TOOL6, tool, fail=:, fail=:, $path)
test "$ac_cv_path_TOOL6" = "$pwd/path/6/better" || fail=:

# A blank pre-set does not bypass feature test
TOOL7=
AC_PATH_PROGS_FEATURE_CHECK(TOOL7, [tool better],
  [$ac_path_TOOL7 && ac_cv_path_TOOL7=$ac_path_TOOL7 ac_path_TOOL7_found=:],
  fail=:, $path)
test -z "$TOOL7" || fail=:
test "$ac_cv_path_TOOL7" = "$pwd/path/1/tool" || fail=:

# No AC-OUTPUT, we don't need config.status.
$fail &&
  AC_MSG_ERROR([[PATH_PROG failed]])
AS_EXIT(0)
]])

AT_CHECK_AUTOCONF
AT_CHECK_CONFIGURE

AT_CLEANUP




## -------------- ##
## AC_PATH_XTRA.  ##
## -------------- ##


AT_SETUP([AC_PATH_XTRA])

_AT_CHECK_AC_MACRO([AC_PATH_XTRA])

# Check X_DISPLAY_MISSING.
AT_CHECK_CONFIGURE([--without-x])
AT_CHECK_DEFINES(
[#define X_DISPLAY_MISSING 1
])

AT_CLEANUP


## ------------------------------- ##
## Obsolete non-updatable macros.  ##
## ------------------------------- ##


AT_CHECK_MACRO([AC_SYS_RESTARTABLE_SYSCALLS], , ,[-W no-obsolete])
AT_CHECK_MACRO([AC_FUNC_SETVBUF_REVERSED], , ,[-W no-obsolete])
AT_CHECK_MACRO([AC_FUNC_WAIT3], , ,[-W no-obsolete])