tests/c.at - autoconf - Git at Google

 #							-*- Autotest -*-

 AT_BANNER([C low level compiling/preprocessing macros.])

 # Copyright (C) 2000-2006, 2008-2017, 2020-2024 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 <https://www.gnu.org/licenses/>.


 # Since the macros which compile are required by most tests, check
 # them first.  But remember that looking for a compiler is even more
 # primitive, so check those first.


 ## ------------ ##
 ## Extensions.  ##
 ## ------------ ##

 AT_CHECK_CONFIGURE_AC([Object file extensions],
 [[AC_PROG_CC

 # As far as we know only 'foo', 'foo.exe' are possible executable,
 # and 'foo.o', 'foo.obj' are possible object files.  Autoconf must not
 # know that, but it is OK for the test suite to take this into account.
 AS@&t@_CASE([$ac_exeext],
   ['' | '.exe'],
     [],
     [AC_MSG_ERROR([suspicious executable suffix: $ac_exeext])])

 AS@&t@_CASE([$ac_objext],
   ['o' | 'obj'],
     [],
     [AC_MSG_ERROR([suspicious object suffix: $ac_objext])])

 AC_OUTPUT
 ]])


 ## -------------------------- ##
 ## Broken/missing compilers.  ##
 ## -------------------------- ##


 # Check that Autoconf correctly diagnoses broken compilers, and in
 # particular, if it does not exit 77, the test suite is in trouble...
 # FIXME: Once a precise message decided, check stderr of configure.
 AT_SETUP([Broken/missing compilers])

 AT_DATA([configure.ac],
 [[AC_INIT
 AC_PROG_CC
 AC_OUTPUT
 ]])

 AT_CHECK_AUTOCONF
 AT_CHECK_CONFIGURE([CC=no-such-compiler], 77, ignore, ignore)

 AT_CLEANUP


 ## ------------ ##
 ## C keywords.  ##
 ## ------------ ##

 AT_CHECK_CONFIGURE_AC([C keywords],
 [[AC_PROG_CC

 AC_C_CONST
 AC_C_TYPEOF
 AC_C_VOLATILE

 # If the C compiler is GCC, AC_C_{CONST,TYPEOF,VOLATILE} ought to all
 # detect support for their respective keyword.
 case $GCC,$ac_cv_c_const,$ac_cv_c_typeof,$ac_cv_c_volatile in
  yes,*no*)
    AC_MSG_ERROR([failed to detect 'const', 'typeof', or 'volatile' support]);;
 esac
 ]])


 ## --------------------------------- ##
 ## AC_PROG_CPP requires AC_PROG_CC.  ##
 ## --------------------------------- ##

 AT_CHECK_CONFIGURE_AC([AC_PROG_CPP requires AC_PROG_CC],
 [[AC_PROG_CPP

 # AC_PROG_CPP should have AC_REQUIREd AC_PROG_CC.
 if test -z "$CC"; then
    AC_MSG_ERROR([looked for a C preprocessor without looking for a compiler])
 fi
 ]])


 ## --------------------------- ##
 ## AC_PROG_CPP with warnings.  ##
 ## --------------------------- ##


 # It's Ok for strict preprocessors to produce warnings.

 AT_SETUP([AC_PROG_CPP with warnings])

 AT_DATA([mycpp],
 [[#! /bin/sh
 echo noise >&2
 exec "$@"
 ]])

 chmod +x mycpp

 _AT_CHECK_AC_MACRO(
 [[AC_PROG_CPP
 # If the preprocessor is not strict, just ignore
 test "x$ac_c_preproc_warn_flag" = xyes &&
   AC_MSG_ERROR([preprocessor has no warning option], 77)
 CPP="./mycpp $CPP"

 # Exercise CPP.

 AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <float.h>]])],
   [AC_DEFINE([HAVE_FLOAT_H], [1], [Define if you have float.h])])
 AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <autoconf_io.h>]])],
   [AC_DEFINE([HAVE_AUTOCONF_IO_H], [1], [Define if you have autoconf_io.h])])
 ]])
 AT_CHECK_DEFINES(
 [/* #undef HAVE_AUTOCONF_IO_H */
 #define HAVE_FLOAT_H 1
 ])

 AT_CLEANUP


 ## ------------------------------ ##
 ## AC_PROG_CPP without warnings.  ##
 ## ------------------------------ ##

 AT_SETUP([AC_PROG_CPP without warnings])

 # Ignore if the cpp in $PATH doesn't work
 AT_CHECK([[echo '#include <stdio.h>' | cpp || exit 77]],
   [], [ignore], [ignore])

 # A cpp which exit status is meaningless.
 AT_DATA([mycpp],
 [[#! /bin/sh
 cpp "$@"
 exit 0
 ]])

 chmod +x mycpp

 _AT_CHECK_AC_MACRO(
 [[CPP=./mycpp
 AC_PROG_CPP
 test "x$ac_c_preproc_warn_flag" != xyes &&
   AC_MSG_ERROR([failed to detect preprocessor warning option])

 # Exercise CPP.
 AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <float.h>]])],
   [AC_DEFINE([HAVE_FLOAT_H], [1], [Define if you have float.h])])
 AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <autoconf_io.h>]])],
   [AC_DEFINE([HAVE_AUTOCONF_IO_H], [1], [Define if you have autoconf_io.h])])
 ]])

 AT_CHECK_DEFINES(
 [/* #undef HAVE_AUTOCONF_IO_H */
 #define HAVE_FLOAT_H 1
 ])

 AT_CLEANUP


 ## -------------------- ##
 ## AC_PROG_CPP via CC.  ##
 ## -------------------- ##


 # It's Ok for strict preprocessors to produce warnings.

 AT_SETUP([AC_PROG_CPP via CC])

 # Ignore if the cpp in $PATH doesn't work
 AT_CHECK([[echo '#include <stdio.h>' | cpp || exit 77]],
   [], [ignore], [ignore])

 AT_DATA([mycc],
 [[#! /bin/sh
 echo "Annoying copyright message" >&2
 exec "$@"
 ]])

 chmod +x mycc

 # We go through the following contortions, in order to have the
 # configure script go down the same codepaths as it would during a
 # normal CPP selection check.  If we explicitly set CPP, it goes down
 # a different codepath.
 _AT_CHECK_AC_MACRO(
 [[AC_PROG_CC
 CC="./mycc $CC"
 AC_PROG_CPP
 # The test $CC compiler should have been selected.
 test "$CPP" != "$CC -E" &&
   AC_MSG_ERROR([error messages on stderr cause the preprocessor selection to fail])

 # Exercise CPP.
 AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <float.h>]])],
   [AC_DEFINE([HAVE_FLOAT_H], [1], [Define if you have float.h])])
 AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <autoconf_io.h>]])],
   [AC_DEFINE([HAVE_AUTOCONF_IO_H], [1], [Define if you have autoconf_io.h])])
 ]])

 AT_CHECK_DEFINES(
 [/* #undef HAVE_AUTOCONF_IO_H */
 #define HAVE_FLOAT_H 1
 ])

 AT_CLEANUP


 ## ----------------------------------- ##
 ## AC_PROG_EGREP and AC_EGREP_HEADER.  ##
 ## ----------------------------------- ##

 AT_SETUP([AC_PROG_EGREP and AC_EGREP_HEADER])

 _AT_CHECK_AC_MACRO(
 [[AC_PROG_CPP
   AC_PROG_EGREP

   # Although this code is incorrect (it should use AS_IF),
   # it follows a too-common real world pattern.
   # For now, test for it; we may remove this test later.
   if false; then
     AC_EGREP_HEADER([^], [limits.h])
   fi

   AC_EGREP_HEADER([$], [limits.h], [],
     [AC_MSG_ERROR([[egrep-related macros do not tolerate misuse of 'if']])])
 ]])

 AT_CLEANUP


 ## ------------------------------------ ##
 ## AC_NO_EXECUTABLES (working linker).  ##
 ## ------------------------------------ ##

 AT_CHECK_CONFIGURE_AC([AC_NO_EXECUTABLES (working linker)],
 [[AC_NO_EXECUTABLES
 AC_PROG_CC
 ]])


 ## ----------------------------------- ##
 ## AC_NO_EXECUTABLES (broken linker).  ##
 ## ----------------------------------- ##

 AT_CHECK_CONFIGURE_AC([AC_NO_EXECUTABLES (broken linker)],
 [[LDFLAGS=-lnosuchlibrary
 AC_NO_EXECUTABLES
 AC_PROG_CC
 ]])


 ## -------------------------- ##
 ## AC_USE_SYSTEM_EXTENSIONS.  ##
 ## -------------------------- ##

 AT_SETUP([AC_USE_SYSTEM_EXTENSIONS])

 # Some existing configure.ac mixed AC_AIX (now an alias for
 # AC_USE_SYSTEM_EXTENSIONS) and AC_DEFINE([__EXTENSIONS__]), which
 # broke autoheader in 2.62.  Test that this is supported.

 _AT_CHECK_AC_MACRO(
 [[AC_AIX
 AC_DEFINE([__EXTENSIONS__], [1], [Manually defined for Solaris])
 ]], [], [-Wno-obsolete])

 _AT_CHECK_AC_MACRO(
 [[AC_USE_SYSTEM_EXTENSIONS
 AC_DEFINE([__EXTENSIONS__], [1], [Manually defined for Solaris])
 ]])

 AT_CLEANUP


 ## ----------------------- ##
 ## AC_C_RESTRICT and C++.  ##
 ## ----------------------- ##

 AT_SETUP([AC_C_RESTRICT and C++])

 # In some compiler suites, the left hand doesn't know about everything
 # the right hand does; or the user mixes the C compiler from one suite
 # with the C++ compiler from another.  In this case, Sun WorkShop CC
 # not like the _Restrict accepted by cc.

 AT_DATA([configure.ac],
 [[AC_INIT
 AC_PROG_CC
 AC_PROG_CXX
 AC_C_RESTRICT
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT
 ]])

 AT_DATA([Makefile.in],
 [[CC = @CC@
 CXX = @CXX@
 CFLAGS = @CFLAGS@
 CXXFLAGS = @CXXFLAGS@
 CPPFLAGS = -I. @CPPFLAGS@
 OBJEXT = @OBJEXT@
 all: foo.$(OBJEXT) bar.$(OBJEXT)
 cpp-works:
 	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c cpp-works.cpp
 foo.$(OBJEXT): foo.c
 	$(CC) $(CPPFLAGS) $(CFLAGS) -c foo.c
 bar.$(OBJEXT): bar.cpp
 	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c bar.cpp
 ]])

 AT_DATA([foo.c],
 [[#include <config.h>

 int foo (int * restrict i1, int * restrict i2)
 {
   return i1[0] + i2[0];
 }
 ]])

 cp foo.c bar.cpp

 AT_DATA([cpp-works.cpp],
 [[// This file is just to test whether we have a working C++ compiler at all
 class foo { int x; };
 class foo foobar;
 ]])

 AT_CHECK_AUTOCONF
 AT_CHECK_AUTOHEADER([], [restrict])
 AT_CHECK_CONFIGURE
 AT_CHECK_MAKE([cpp-works || exit 77])
 AT_CHECK_MAKE

 AT_CLEANUP


 ## ---------------- ##
 ## AC_OPENMP and C. ##
 ## ---------------- ##

 AT_SETUP([AC_OPENMP and C])

 AT_DATA([configure.ac],
 [[AC_INIT
 AC_PROG_CC
 AC_OPENMP
 if test "X$ac_cv_prog_c_openmp" = Xunsupported; then
   AS_EXIT([77])
 fi
 CFLAGS="$CFLAGS $OPENMP_CFLAGS"
 CPPFLAGS="$CPPFLAGS $OPENMP_CFLAGS"
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT
 ]])

 AT_DATA([Makefile.in],
 [[foo@EXEEXT@: foo.@OBJEXT@
 	@CC@ @CFLAGS@ @LDFLAGS@ -o $@ foo.@OBJEXT@

 foo.@OBJEXT@: foo.c
 	@CC@ @CPPFLAGS@ @CFLAGS@ -c foo.c
 ]])

 AT_DATA([foo.c],
 [[#ifdef _OPENMP
 #include <omp.h>
 #endif
 #include <stdio.h>

 int main (void)
 {
 #ifdef _OPENMP
 #pragma omp parallel
   {
     int id = omp_get_thread_num ();
     printf ("hello omp world from %d\n", id);
   }
 #endif
   return 0;
 }
 ]])

 AT_CHECK_AUTOCONF
 AT_CHECK_CONFIGURE
 AT_CHECK_MAKE

 AT_CLEANUP


 ## ------------------ ##
 ## AC_OPENMP anc C++. ##
 ## ------------------ ##

 AT_SETUP([AC_OPENMP and C++])

 AT_DATA([configure.ac],
 [[AC_INIT
 AC_PROG_CXX
 AC_LANG([C++])
 AC_OPENMP
 if test "X$ac_cv_prog_cxx_openmp" = Xunsupported; then
   AS_EXIT([77])
 fi
 CXXFLAGS="$CXXFLAGS $OPENMP_CXXFLAGS"
 CPPFLAGS="$CPPFLAGS $OPENMP_CXXFLAGS"
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT
 ]])

 AT_DATA([Makefile.in],
 [[foo@EXEEXT@: foo.@OBJEXT@
 	@CXX@ @CXXFLAGS@ @LDFLAGS@ -o $@ foo.@OBJEXT@

 foo.@OBJEXT@: foo.cpp
 	@CXX@ @CPPFLAGS@ @CXXFLAGS@ -c foo.cpp
 ]])

 AT_DATA([foo.cpp],
 [[int main (void)
 {
   return 0;
 }
 ]])

 AT_CHECK_AUTOCONF
 AT_CHECK_CONFIGURE
 AT_CHECK_MAKE

 AT_CLEANUP
	# -- Autotest --

	AT_BANNER([C low level compiling/preprocessing macros.])

	# Copyright (C) 2000-2006, 2008-2017, 2020-2024 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 <https://www.gnu.org/licenses/>.


	# Since the macros which compile are required by most tests, check
	# them first. But remember that looking for a compiler is even more
	# primitive, so check those first.


	## ------------ ##
	## Extensions. ##
	## ------------ ##

	AT_CHECK_CONFIGURE_AC([Object file extensions],
	[[AC_PROG_CC

	# As far as we know only 'foo', 'foo.exe' are possible executable,
	# and 'foo.o', 'foo.obj' are possible object files. Autoconf must not
	# know that, but it is OK for the test suite to take this into account.
	AS@&t@_CASE([$ac_exeext],
	['' \| '.exe'],
	[],
	[AC_MSG_ERROR([suspicious executable suffix: $ac_exeext])])

	AS@&t@_CASE([$ac_objext],
	['o' \| 'obj'],
	[],
	[AC_MSG_ERROR([suspicious object suffix: $ac_objext])])

	AC_OUTPUT
	]])


	## -------------------------- ##
	## Broken/missing compilers. ##
	## -------------------------- ##


	# Check that Autoconf correctly diagnoses broken compilers, and in
	# particular, if it does not exit 77, the test suite is in trouble...
	# FIXME: Once a precise message decided, check stderr of configure.
	AT_SETUP([Broken/missing compilers])

	AT_DATA([configure.ac],
	[[AC_INIT
	AC_PROG_CC
	AC_OUTPUT
	]])

	AT_CHECK_AUTOCONF
	AT_CHECK_CONFIGURE([CC=no-such-compiler], 77, ignore, ignore)

	AT_CLEANUP


	## ------------ ##
	## C keywords. ##
	## ------------ ##

	AT_CHECK_CONFIGURE_AC([C keywords],
	[[AC_PROG_CC

	AC_C_CONST
	AC_C_TYPEOF
	AC_C_VOLATILE

	# If the C compiler is GCC, AC_C_{CONST,TYPEOF,VOLATILE} ought to all
	# detect support for their respective keyword.
	case $GCC,$ac_cv_c_const,$ac_cv_c_typeof,$ac_cv_c_volatile in
	yes,no)
	AC_MSG_ERROR([failed to detect 'const', 'typeof', or 'volatile' support]);;
	esac
	]])


	## --------------------------------- ##
	## AC_PROG_CPP requires AC_PROG_CC. ##
	## --------------------------------- ##

	AT_CHECK_CONFIGURE_AC([AC_PROG_CPP requires AC_PROG_CC],
	[[AC_PROG_CPP

	# AC_PROG_CPP should have AC_REQUIREd AC_PROG_CC.
	if test -z "$CC"; then
	AC_MSG_ERROR([looked for a C preprocessor without looking for a compiler])
	fi
	]])


	## --------------------------- ##
	## AC_PROG_CPP with warnings. ##
	## --------------------------- ##


	# It's Ok for strict preprocessors to produce warnings.

	AT_SETUP([AC_PROG_CPP with warnings])

	AT_DATA([mycpp],
	[[#! /bin/sh
	echo noise >&2
	exec "$@"
	]])

	chmod +x mycpp

	_AT_CHECK_AC_MACRO(
	[[AC_PROG_CPP
	# If the preprocessor is not strict, just ignore
	test "x$ac_c_preproc_warn_flag" = xyes &&
	AC_MSG_ERROR([preprocessor has no warning option], 77)
	CPP="./mycpp $CPP"

	# Exercise CPP.

	AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <float.h>]])],
	[AC_DEFINE([HAVE_FLOAT_H], [1], [Define if you have float.h])])
	AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <autoconf_io.h>]])],
	[AC_DEFINE([HAVE_AUTOCONF_IO_H], [1], [Define if you have autoconf_io.h])])
	]])
	AT_CHECK_DEFINES(
	[/* #undef HAVE_AUTOCONF_IO_H */
	#define HAVE_FLOAT_H 1
	])

	AT_CLEANUP


	## ------------------------------ ##
	## AC_PROG_CPP without warnings. ##
	## ------------------------------ ##

	AT_SETUP([AC_PROG_CPP without warnings])

	# Ignore if the cpp in $PATH doesn't work
	AT_CHECK([[echo '#include <stdio.h>' \| cpp \|\| exit 77]],
	[], [ignore], [ignore])

	# A cpp which exit status is meaningless.
	AT_DATA([mycpp],
	[[#! /bin/sh
	cpp "$@"
	exit 0
	]])

	chmod +x mycpp

	_AT_CHECK_AC_MACRO(
	[[CPP=./mycpp
	AC_PROG_CPP
	test "x$ac_c_preproc_warn_flag" != xyes &&
	AC_MSG_ERROR([failed to detect preprocessor warning option])

	# Exercise CPP.
	AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <float.h>]])],
	[AC_DEFINE([HAVE_FLOAT_H], [1], [Define if you have float.h])])
	AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <autoconf_io.h>]])],
	[AC_DEFINE([HAVE_AUTOCONF_IO_H], [1], [Define if you have autoconf_io.h])])
	]])

	AT_CHECK_DEFINES(
	[/* #undef HAVE_AUTOCONF_IO_H */
	#define HAVE_FLOAT_H 1
	])

	AT_CLEANUP



	## -------------------- ##
	## AC_PROG_CPP via CC. ##
	## -------------------- ##


	# It's Ok for strict preprocessors to produce warnings.

	AT_SETUP([AC_PROG_CPP via CC])

	# Ignore if the cpp in $PATH doesn't work
	AT_CHECK([[echo '#include <stdio.h>' \| cpp \|\| exit 77]],
	[], [ignore], [ignore])

	AT_DATA([mycc],
	[[#! /bin/sh
	echo "Annoying copyright message" >&2
	exec "$@"
	]])

	chmod +x mycc

	# We go through the following contortions, in order to have the
	# configure script go down the same codepaths as it would during a
	# normal CPP selection check. If we explicitly set CPP, it goes down
	# a different codepath.
	_AT_CHECK_AC_MACRO(
	[[AC_PROG_CC
	CC="./mycc $CC"
	AC_PROG_CPP
	# The test $CC compiler should have been selected.
	test "$CPP" != "$CC -E" &&
	AC_MSG_ERROR([error messages on stderr cause the preprocessor selection to fail])

	# Exercise CPP.
	AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <float.h>]])],
	[AC_DEFINE([HAVE_FLOAT_H], [1], [Define if you have float.h])])
	AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <autoconf_io.h>]])],
	[AC_DEFINE([HAVE_AUTOCONF_IO_H], [1], [Define if you have autoconf_io.h])])
	]])

	AT_CHECK_DEFINES(
	[/* #undef HAVE_AUTOCONF_IO_H */
	#define HAVE_FLOAT_H 1
	])

	AT_CLEANUP


	## ----------------------------------- ##
	## AC_PROG_EGREP and AC_EGREP_HEADER. ##
	## ----------------------------------- ##

	AT_SETUP([AC_PROG_EGREP and AC_EGREP_HEADER])

	_AT_CHECK_AC_MACRO(
	[[AC_PROG_CPP
	AC_PROG_EGREP

	# Although this code is incorrect (it should use AS_IF),
	# it follows a too-common real world pattern.
	# For now, test for it; we may remove this test later.
	if false; then
	AC_EGREP_HEADER([^], [limits.h])
	fi

	AC_EGREP_HEADER([$], [limits.h], [],
	[AC_MSG_ERROR([[egrep-related macros do not tolerate misuse of 'if']])])
	]])

	AT_CLEANUP


	## ------------------------------------ ##
	## AC_NO_EXECUTABLES (working linker). ##
	## ------------------------------------ ##

	AT_CHECK_CONFIGURE_AC([AC_NO_EXECUTABLES (working linker)],
	[[AC_NO_EXECUTABLES
	AC_PROG_CC
	]])


	## ----------------------------------- ##
	## AC_NO_EXECUTABLES (broken linker). ##
	## ----------------------------------- ##

	AT_CHECK_CONFIGURE_AC([AC_NO_EXECUTABLES (broken linker)],
	[[LDFLAGS=-lnosuchlibrary
	AC_NO_EXECUTABLES
	AC_PROG_CC
	]])


	## -------------------------- ##
	## AC_USE_SYSTEM_EXTENSIONS. ##
	## -------------------------- ##

	AT_SETUP([AC_USE_SYSTEM_EXTENSIONS])

	# Some existing configure.ac mixed AC_AIX (now an alias for
	# AC_USE_SYSTEM_EXTENSIONS) and AC_DEFINE([__EXTENSIONS__]), which
	# broke autoheader in 2.62. Test that this is supported.

	_AT_CHECK_AC_MACRO(
	[[AC_AIX
	AC_DEFINE([__EXTENSIONS__], [1], [Manually defined for Solaris])
	]], [], [-Wno-obsolete])

	_AT_CHECK_AC_MACRO(
	[[AC_USE_SYSTEM_EXTENSIONS
	AC_DEFINE([__EXTENSIONS__], [1], [Manually defined for Solaris])
	]])

	AT_CLEANUP


	## ----------------------- ##
	## AC_C_RESTRICT and C++. ##
	## ----------------------- ##

	AT_SETUP([AC_C_RESTRICT and C++])

	# In some compiler suites, the left hand doesn't know about everything
	# the right hand does; or the user mixes the C compiler from one suite
	# with the C++ compiler from another. In this case, Sun WorkShop CC
	# not like the _Restrict accepted by cc.

	AT_DATA([configure.ac],
	[[AC_INIT
	AC_PROG_CC
	AC_PROG_CXX
	AC_C_RESTRICT
	AC_CONFIG_HEADERS([config.h])
	AC_CONFIG_FILES([Makefile])
	AC_OUTPUT
	]])

	AT_DATA([Makefile.in],
	[[CC = @CC@
	CXX = @CXX@
	CFLAGS = @CFLAGS@
	CXXFLAGS = @CXXFLAGS@
	CPPFLAGS = -I. @CPPFLAGS@
	OBJEXT = @OBJEXT@
	all: foo.$(OBJEXT) bar.$(OBJEXT)
	cpp-works:
	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c cpp-works.cpp
	foo.$(OBJEXT): foo.c
	$(CC) $(CPPFLAGS) $(CFLAGS) -c foo.c
	bar.$(OBJEXT): bar.cpp
	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c bar.cpp
	]])

	AT_DATA([foo.c],
	[[#include <config.h>

	int foo (int * restrict i1, int * restrict i2)
	{
	return i1[0] + i2[0];
	}
	]])

	cp foo.c bar.cpp

	AT_DATA([cpp-works.cpp],
	[[// This file is just to test whether we have a working C++ compiler at all
	class foo { int x; };
	class foo foobar;
	]])

	AT_CHECK_AUTOCONF
	AT_CHECK_AUTOHEADER([], [restrict])
	AT_CHECK_CONFIGURE
	AT_CHECK_MAKE([cpp-works \|\| exit 77])
	AT_CHECK_MAKE

	AT_CLEANUP


	## ---------------- ##
	## AC_OPENMP and C. ##
	## ---------------- ##

	AT_SETUP([AC_OPENMP and C])

	AT_DATA([configure.ac],
	[[AC_INIT
	AC_PROG_CC
	AC_OPENMP
	if test "X$ac_cv_prog_c_openmp" = Xunsupported; then
	AS_EXIT([77])
	fi
	CFLAGS="$CFLAGS $OPENMP_CFLAGS"
	CPPFLAGS="$CPPFLAGS $OPENMP_CFLAGS"
	AC_CONFIG_FILES([Makefile])
	AC_OUTPUT
	]])

	AT_DATA([Makefile.in],
	[[foo@EXEEXT@: foo.@OBJEXT@
	@CC@ @CFLAGS@ @LDFLAGS@ -o $@ foo.@OBJEXT@

	foo.@OBJEXT@: foo.c
	@CC@ @CPPFLAGS@ @CFLAGS@ -c foo.c
	]])

	AT_DATA([foo.c],
	[[#ifdef _OPENMP
	#include <omp.h>
	#endif
	#include <stdio.h>

	int main (void)
	{
	#ifdef _OPENMP
	#pragma omp parallel
	{
	int id = omp_get_thread_num ();
	printf ("hello omp world from %d\n", id);
	}
	#endif
	return 0;
	}
	]])

	AT_CHECK_AUTOCONF
	AT_CHECK_CONFIGURE
	AT_CHECK_MAKE

	AT_CLEANUP


	## ------------------ ##
	## AC_OPENMP anc C++. ##
	## ------------------ ##

	AT_SETUP([AC_OPENMP and C++])

	AT_DATA([configure.ac],
	[[AC_INIT
	AC_PROG_CXX
	AC_LANG([C++])
	AC_OPENMP
	if test "X$ac_cv_prog_cxx_openmp" = Xunsupported; then
	AS_EXIT([77])
	fi
	CXXFLAGS="$CXXFLAGS $OPENMP_CXXFLAGS"
	CPPFLAGS="$CPPFLAGS $OPENMP_CXXFLAGS"
	AC_CONFIG_FILES([Makefile])
	AC_OUTPUT
	]])

	AT_DATA([Makefile.in],
	[[foo@EXEEXT@: foo.@OBJEXT@
	@CXX@ @CXXFLAGS@ @LDFLAGS@ -o $@ foo.@OBJEXT@

	foo.@OBJEXT@: foo.cpp
	@CXX@ @CPPFLAGS@ @CXXFLAGS@ -c foo.cpp
	]])

	AT_DATA([foo.cpp],
	[[int main (void)
	{
	return 0;
	}
	]])

	AT_CHECK_AUTOCONF
	AT_CHECK_CONFIGURE
	AT_CHECK_MAKE

	AT_CLEANUP