root/branches/dp2mp-move/base/objc.m4

# objc.m4
# Based on c.m4 from GNU Autoconf
# The Objective C support, added by Landon Fuller <landonf@opendarwin.org>
# on March 10th, 2004, is heavily based on Autoconf's existing C++ support.
#
########### Copyright and Licensing terms ##########
#
# This file is part of Autoconf.                       -*- Autoconf -*-
# Programming languages support.
# Copyright (C) 2001, 2002, 2003 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 2, 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.
#
# As a special exception, the Free Software Foundation gives unlimited
# permission to copy, distribute and modify the configure scripts that
# are the output of Autoconf.  You need not follow the terms of the GNU
# General Public License when using or distributing such scripts, even
# though portions of the text of Autoconf appear in them.  The GNU
# General Public License (GPL) does govern all other use of the material
# that constitutes the Autoconf program.
#
# Certain portions of the Autoconf source text are designed to be copied
# (in certain cases, depending on the input) into the output of
# Autoconf.  We call these the "data" portions.  The rest of the Autoconf
# source text consists of comments plus executable code that decides which
# of the data portions to output in any given case.  We call these
# comments and executable code the "non-data" portions.  Autoconf never
# copies any of the non-data portions into its output.
#
# This special exception to the GPL applies to versions of Autoconf
# released by the Free Software Foundation.  When you make and
# distribute a modified version of Autoconf, you may extend this special
# exception to the GPL to apply to your modified version as well, *unless*
# your modified version has the potential to copy into its output some
# of the text that was the non-data portion of the version that you started
# with.  (In other words, unless your change moves or copies text from
# the non-data portions to the data portions.)  If your modification has
# such potential, you must delete any notice of this special exception
# to the GPL from your modified version.
#
# Written by David MacKenzie, with help from
# Franc,ois Pinard, Karl Berry, Richard Pixley, Ian Lance Taylor,
# Roland McGrath, Noah Friedman, david d zuhn, and many others.
#
########## GNU General Public License (GPL), version 2  ##########
#
#                   GNU GENERAL PUBLIC LICENSE
#                      Version 2, June 1991
#
#  Copyright (C) 1989, 1991 Free Software Foundation, Inc.
#      59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#  Everyone is permitted to copy and distribute verbatim copies
#  of this license document, but changing it is not allowed.
#
#                           Preamble
# 
#  The licenses for most software are designed to take away your
# freedom to share and change it.  By contrast, the GNU General Public
# License is intended to guarantee your freedom to share and change free
# software--to make sure the software is free for all its users.  This
# General Public License applies to most of the Free Software
# Foundation's software and to any other program whose authors commit to
# using it.  (Some other Free Software Foundation software is covered by
# the GNU Library General Public License instead.)  You can apply it to
# your programs, too.
#
#  When we speak of free software, we are referring to freedom, not
# price.  Our General Public Licenses are designed to make sure that you
# have the freedom to distribute copies of free software (and charge for
# this service if you wish), that you receive source code or can get it
# if you want it, that you can change the software or use pieces of it
# in new free programs; and that you know you can do these things.
#
#  To protect your rights, we need to make restrictions that forbid
# anyone to deny you these rights or to ask you to surrender the rights.
# These restrictions translate to certain responsibilities for you if you
# distribute copies of the software, or if you modify it.
#
#  For example, if you distribute copies of such a program, whether
# gratis or for a fee, you must give the recipients all the rights that
# you have.  You must make sure that they, too, receive or can get the
# source code.  And you must show them these terms so they know their
# rights.
#
#  We protect your rights with two steps: (1) copyright the software, and
# (2) offer you this license which gives you legal permission to copy,
# distribute and/or modify the software.
#
#  Also, for each author's protection and ours, we want to make certain
# that everyone understands that there is no warranty for this free
# software.  If the software is modified by someone else and passed on, we
# want its recipients to know that what they have is not the original, so
# that any problems introduced by others will not reflect on the original
# authors' reputations.
#
#  Finally, any free program is threatened constantly by software
# patents.  We wish to avoid the danger that redistributors of a free
# program will individually obtain patent licenses, in effect making the
# program proprietary.  To prevent this, we have made it clear that any
# patent must be licensed for everyone's free use or not licensed at all.
#
#  The precise terms and conditions for copying, distribution and
# modification follow.
#
#                   GNU GENERAL PUBLIC LICENSE
#  TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
#
#  0. This License applies to any program or other work which contains
# a notice placed by the copyright holder saying it may be distributed
# under the terms of this General Public License.  The "Program", below,
# refers to any such program or work, and a "work based on the Program"
# means either the Program or any derivative work under copyright law:
# that is to say, a work containing the Program or a portion of it,
# either verbatim or with modifications and/or translated into another
# language.  (Hereinafter, translation is included without limitation in
# the term "modification".)  Each licensee is addressed as "you".
#
# Activities other than copying, distribution and modification are not
# covered by this License; they are outside its scope.  The act of
# running the Program is not restricted, and the output from the Program
# is covered only if its contents constitute a work based on the
# Program (independent of having been made by running the Program).
# Whether that is true depends on what the Program does.
#
#  1. You may copy and distribute verbatim copies of the Program's
# source code as you receive it, in any medium, provided that you
# conspicuously and appropriately publish on each copy an appropriate
# copyright notice and disclaimer of warranty; keep intact all the
# notices that refer to this License and to the absence of any warranty;
# and give any other recipients of the Program a copy of this License
# along with the Program.
#
# You may charge a fee for the physical act of transferring a copy, and
# you may at your option offer warranty protection in exchange for a fee.
#
#  2. You may modify your copy or copies of the Program or any portion
# of it, thus forming a work based on the Program, and copy and
# distribute such modifications or work under the terms of Section 1
# above, provided that you also meet all of these conditions:
#
#    a) You must cause the modified files to carry prominent notices
#    stating that you changed the files and the date of any change.
#
#    b) You must cause any work that you distribute or publish, that in
#    whole or in part contains or is derived from the Program or any
#    part thereof, to be licensed as a whole at no charge to all third
#    parties under the terms of this License.
#
#    c) If the modified program normally reads commands interactively
#    when run, you must cause it, when started running for such
#    interactive use in the most ordinary way, to print or display an
#    announcement including an appropriate copyright notice and a
#    notice that there is no warranty (or else, saying that you provide
#    a warranty) and that users may redistribute the program under
#    these conditions, and telling the user how to view a copy of this
#    License.  (Exception: if the Program itself is interactive but
#    does not normally print such an announcement, your work based on
#    the Program is not required to print an announcement.)
#
# These requirements apply to the modified work as a whole.  If
# identifiable sections of that work are not derived from the Program,
# and can be reasonably considered independent and separate works in
# themselves, then this License, and its terms, do not apply to those
# sections when you distribute them as separate works.  But when you
# distribute the same sections as part of a whole which is a work based
# on the Program, the distribution of the whole must be on the terms of
# this License, whose permissions for other licensees extend to the
# entire whole, and thus to each and every part regardless of who wrote it.
#
# Thus, it is not the intent of this section to claim rights or contest
# your rights to work written entirely by you; rather, the intent is to
# exercise the right to control the distribution of derivative or
# collective works based on the Program.
#
# In addition, mere aggregation of another work not based on the Program
# with the Program (or with a work based on the Program) on a volume of
# a storage or distribution medium does not bring the other work under
# the scope of this License.
#
#  3. You may copy and distribute the Program (or a work based on it,
# under Section 2) in object code or executable form under the terms of
# Sections 1 and 2 above provided that you also do one of the following:
#
#    a) Accompany it with the complete corresponding machine-readable
#    source code, which must be distributed under the terms of Sections
#    1 and 2 above on a medium customarily used for software interchange; or,
#
#    b) Accompany it with a written offer, valid for at least three
#    years, to give any third party, for a charge no more than your
#    cost of physically performing source distribution, a complete
#    machine-readable copy of the corresponding source code, to be
#    distributed under the terms of Sections 1 and 2 above on a medium
#    customarily used for software interchange; or,
#
#    c) Accompany it with the information you received as to the offer
#    to distribute corresponding source code.  (This alternative is
#    allowed only for noncommercial distribution and only if you
#    received the program in object code or executable form with such
#    an offer, in accord with Subsection b above.)
#
# The source code for a work means the preferred form of the work for
# making modifications to it.  For an executable work, complete source
# code means all the source code for all modules it contains, plus any
# associated interface definition files, plus the scripts used to
# control compilation and installation of the executable.  However, as a
# special exception, the source code distributed need not include
# anything that is normally distributed (in either source or binary
# form) with the major components (compiler, kernel, and so on) of the
# operating system on which the executable runs, unless that component
# itself accompanies the executable.
#
# If distribution of executable or object code is made by offering
# access to copy from a designated place, then offering equivalent
# access to copy the source code from the same place counts as
# distribution of the source code, even though third parties are not
# compelled to copy the source along with the object code.
#
#  4. You may not copy, modify, sublicense, or distribute the Program
# except as expressly provided under this License.  Any attempt
# otherwise to copy, modify, sublicense or distribute the Program is
# void, and will automatically terminate your rights under this License.
# However, parties who have received copies, or rights, from you under
# this License will not have their licenses terminated so long as such
# parties remain in full compliance.
#
#  5. You are not required to accept this License, since you have not
# signed it.  However, nothing else grants you permission to modify or
# distribute the Program or its derivative works.  These actions are
# prohibited by law if you do not accept this License.  Therefore, by
# modifying or distributing the Program (or any work based on the
# Program), you indicate your acceptance of this License to do so, and
# all its terms and conditions for copying, distributing or modifying
# the Program or works based on it.

#  6. Each time you redistribute the Program (or any work based on the
# Program), the recipient automatically receives a license from the
# original licensor to copy, distribute or modify the Program subject to
# these terms and conditions.  You may not impose any further
# restrictions on the recipients' exercise of the rights granted herein.
# You are not responsible for enforcing compliance by third parties to
# this License.
#
#  7. If, as a consequence of a court judgment or allegation of patent
# infringement or for any other reason (not limited to patent issues),
# conditions are imposed on you (whether by court order, agreement or
# otherwise) that contradict the conditions of this License, they do not
# excuse you from the conditions of this License.  If you cannot
# distribute so as to satisfy simultaneously your obligations under this
# License and any other pertinent obligations, then as a consequence you
# may not distribute the Program at all.  For example, if a patent
# license would not permit royalty-free redistribution of the Program by
# all those who receive copies directly or indirectly through you, then
# the only way you could satisfy both it and this License would be to
# refrain entirely from distribution of the Program.
#
# If any portion of this section is held invalid or unenforceable under
# any particular circumstance, the balance of the section is intended to
# apply and the section as a whole is intended to apply in other
# circumstances.
#
# It is not the purpose of this section to induce you to infringe any
# patents or other property right claims or to contest validity of any
# such claims; this section has the sole purpose of protecting the
# integrity of the free software distribution system, which is
# implemented by public license practices.  Many people have made
# generous contributions to the wide range of software distributed
# through that system in reliance on consistent application of that
# system; it is up to the author/donor to decide if he or she is willing
# to distribute software through any other system and a licensee cannot
# impose that choice.
#
# This section is intended to make thoroughly clear what is believed to
# be a consequence of the rest of this License.
#
#  8. If the distribution and/or use of the Program is restricted in
# certain countries either by patents or by copyrighted interfaces, the
# original copyright holder who places the Program under this License
# may add an explicit geographical distribution limitation excluding
# those countries, so that distribution is permitted only in or among
# countries not thus excluded.  In such case, this License incorporates
# the limitation as if written in the body of this License.
#
#  9. The Free Software Foundation may publish revised and/or new versions
# of the General Public License from time to time.  Such new versions will
# be similar in spirit to the present version, but may differ in detail to
# address new problems or concerns.
#
# Each version is given a distinguishing version number.  If the Program
# specifies a version number of this License which applies to it and "any
# later version", you have the option of following the terms and conditions
# either of that version or of any later version published by the Free
# Software Foundation.  If the Program does not specify a version number of
# this License, you may choose any version ever published by the Free Software
# Foundation.
#
#  10. If you wish to incorporate parts of the Program into other free
# programs whose distribution conditions are different, write to the author
# to ask for permission.  For software which is copyrighted by the Free
# Software Foundation, write to the Free Software Foundation; we sometimes
# make exceptions for this.  Our decision will be guided by the two goals
# of preserving the free status of all derivatives of our free software and
# of promoting the sharing and reuse of software generally.
#
#                           NO WARRANTY
#
#  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
# FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
# OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
# PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
# OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
# TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
# PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
# REPAIR OR CORRECTION.
#
#  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
# WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
# REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
# INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
# OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
# TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
# YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
# PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGES.
#
#                    END OF TERMS AND CONDITIONS
#
#           How to Apply These Terms to Your New Programs
#
#  If you develop a new program, and you want it to be of the greatest
# possible use to the public, the best way to achieve this is to make it
# free software which everyone can redistribute and change under these terms.
#
#  To do so, attach the following notices to the program.  It is safest
# to attach them to the start of each source file to most effectively
# convey the exclusion of warranty; and each file should have at least
# the "copyright" line and a pointer to where the full notice is found.
#
#    <one line to give the program's name and a brief idea of what it does.>
#    Copyright (C) <year>  <name of author>
#
#    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 2 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, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#
# Also add information on how to contact you by electronic and paper mail.
#
# If the program is interactive, make it output a short notice like this
# when it starts in an interactive mode:
#
#    Gnomovision version 69, Copyright (C) year  name of author
#    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
#    This is free software, and you are welcome to redistribute it
#    under certain conditions; type `show c' for details.
#
# The hypothetical commands `show w' and `show c' should show the appropriate
# parts of the General Public License.  Of course, the commands you use may
# be called something other than `show w' and `show c'; they could even be
# mouse-clicks or menu items--whatever suits your program.
#
# You should also get your employer (if you work as a programmer) or your
# school, if any, to sign a "copyright disclaimer" for the program, if
# necessary.  Here is a sample; alter the names:
#
#  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
#  `Gnomovision' (which makes passes at compilers) written by James Hacker.
#
#  <signature of Ty Coon>, 1 April 1989
#  Ty Coon, President of Vice
#
# This General Public License does not permit incorporating your program into
# proprietary programs.  If your program is a subroutine library, you may
# consider it more useful to permit linking proprietary applications with the
# library.  If this is what you want to do, use the GNU Library General
# Public License instead of this License.
#
########## End of GNU General Public License (GPL), version 2 ##########

## ----------------------- ##
## 1. Language selection.  ##
## ----------------------- ##


# ------------------------------ #
# 1d. The Objective C language.  #
# ------------------------------ #

# AC_LANG(Objective C)
# --------------------
# OBJCFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
m4_define([AC_LANG(Objective C)],
[ac_ext=m
ac_cpp='$OBJCPP $CPPFLAGS'
ac_compile='$OBJC -c $OBJCFLAGS $CPPFLAGS conftest.$ac_ext >&AS_MESSAGE_LOG_FD'
ac_link='$OBJC -o conftest$ac_exeext $OBJCFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&AS_MESSAGE_LOG_FD'
ac_compiler_gnu=$ac_cv_objc_compiler_gnu
])


# AC_LANG_OBJC
# -------------------------
AU_DEFUN([AC_LANG_OBJC], [AC_LANG(Objective C)])


# _AC_LANG_ABBREV(Objective C)
# ----------------------------
m4_define([_AC_LANG_ABBREV(Objective C)], [objc])


# _AC_LANG_PREFIX(Objective C)
# ----------------------------
m4_define([_AC_LANG_PREFIX(Objective C)], [OBJC])



## ---------------------- ##
## 2.Producing programs.  ##
## ---------------------- ##


# ------------------------- #
# 2d. Objective C sources.  #
# ------------------------- #

# AC_LANG_SOURCE(Objective C)(BODY)
# ---------------------------------
m4_copy([AC_LANG_SOURCE(C)], [AC_LANG_SOURCE(Objective C)])


# AC_LANG_PROGRAM(Objective C)([PROLOGUE], [BODY])
# ------------------------------------------------
m4_copy([AC_LANG_PROGRAM(C)], [AC_LANG_PROGRAM(Objective C)])


# AC_LANG_CALL(Objective C)(PROLOGUE, FUNCTION)
# ---------------------------------------------
m4_copy([AC_LANG_CALL(C)], [AC_LANG_CALL(Objective C)])


# AC_LANG_FUNC_LINK_TRY(Objective C)(FUNCTION)
# --------------------------------------------
m4_copy([AC_LANG_FUNC_LINK_TRY(C)], [AC_LANG_FUNC_LINK_TRY(Objective C)])


# AC_LANG_BOOL_COMPILE_TRY(Objective C)(PROLOGUE, EXPRESSION)
# -----------------------------------------------------------
m4_copy([AC_LANG_BOOL_COMPILE_TRY(C)], [AC_LANG_BOOL_COMPILE_TRY(Objective C)])


# AC_LANG_INT_SAVE(Objective C)(PROLOGUE, EXPRESSION)
# ---------------------------------------------------
m4_copy([AC_LANG_INT_SAVE(C)], [AC_LANG_INT_SAVE(Objective C)])



## -------------------------------------------- ##
## 3. Looking for Compilers and Preprocessors.  ##
## -------------------------------------------- ##


# ------------------------------ #
# 3d. The Objective C compiler.  #
# ------------------------------ #


# AC_LANG_PREPROC(Objecitve C)
# ----------------------------
# Find the Objective C preprocessor.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
AC_DEFUN([AC_LANG_PREPROC(Objective C)],
[AC_REQUIRE([AC_PROG_OBJCPP])])


# AC_PROG_OBJCPP
# --------------
# Find a working Objective C preprocessor.
# We shouldn't have to require AC_PROG_CC, but this is due to the concurrency
# between the AC_LANG_COMPILER_REQUIRE family and that of AC_PROG_OBJC.
AC_DEFUN([AC_PROG_OBJCPP],
[AC_REQUIRE([AC_PROG_OBJC])dnl
AC_ARG_VAR([OBJCPP],   [Objective C preprocessor])dnl
_AC_ARG_VAR_CPPFLAGS()dnl
AC_LANG_PUSH(Objective C)dnl
AC_MSG_CHECKING([how to run the Objective C preprocessor])
if test -z "$OBJCPP"; then
  AC_CACHE_VAL(ac_cv_prog_OBJCPP,
  [dnl
    # Double quotes because OBJCPP needs to be expanded
    for OBJCPP in "$OBJC -E" "/lib/cpp"
    do
      _AC_PROG_PREPROC_WORKS_IFELSE([break])
    done
    ac_cv_prog_OBJCPP=$OBJCPP
  ])dnl
  OBJCPP=$ac_cv_prog_OBJCPP
else
  ac_cv_prog_OBJCPP=$OBJCPP
fi
AC_MSG_RESULT([$OBJCPP])
_AC_PROG_PREPROC_WORKS_IFELSE([],
          [AC_MSG_FAILURE([Objective C preprocessor "$OBJCPP" fails sanity check])])
AC_SUBST(OBJCPP)dnl
AC_LANG_POP(Objective C)dnl
])# AC_PROG_OBJCPP


# AC_LANG_COMPILER(Objective C)
# -----------------------------
# Find the Objective C compiler.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
AC_DEFUN([AC_LANG_COMPILER(Objective C)],
[AC_REQUIRE([AC_PROG_OBJC])])


# ac_cv_prog_objc
# ---------------
# We used to name the cache variable this way.
AU_DEFUN([ac_cv_prog_objc],
[ac_cv_objc_compiler_gnu])


# AC_PROG_OBJC([LIST-OF-COMPILERS])
# ---------------------------------
# LIST-OF-COMPILERS is a space separated list of Objective C compilers
# to search for (if not specified, a default list is used).  This just gives
# the user an opportunity to specify an alternative search list for the
# Objective C compiler.
# cc    Native compiler
# objc  David Stes' Portable Object Compiler
AN_MAKEVAR([OBJC],  [AC_PROG_OBJC])
AN_PROGRAM([gcc],   [AC_PROG_OBJC])
AN_PROGRAM([cc],    [AC_PROG_OBJC])
AC_DEFUN([AC_PROG_OBJC],
[AC_LANG_PUSH(Objective C)dnl
AC_ARG_VAR([OBJC],      [Objective C compiler command])dnl
AC_ARG_VAR([OBJCFLAGS], [Objective C compiler flags])dnl
_AC_ARG_VAR_LDFLAGS()dnl
_AC_ARG_VAR_CPPFLAGS()dnl
AC_CHECK_TOOLS(OBJC,
               [$CCC m4_default([$1],
                          [gcc cc objc])],
               gcc)

# Provide some information about the compiler.
echo "$as_me:$LINENO:" \
     "checking for _AC_LANG compiler version" >&AS_MESSAGE_LOG_FD
ac_compiler=`set X $ac_compile; echo $[2]`
_AC_EVAL([$ac_compiler --version </dev/null >&AS_MESSAGE_LOG_FD])
_AC_EVAL([$ac_compiler -v </dev/null >&AS_MESSAGE_LOG_FD])
_AC_EVAL([$ac_compiler -V </dev/null >&AS_MESSAGE_LOG_FD])

m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
m4_expand_once([_AC_COMPILER_OBJEXT])[]dnl
_AC_LANG_COMPILER_GNU
GOBJC=`test $ac_compiler_gnu = yes && echo yes`
_AC_PROG_OBJC_G
AC_LANG_POP(Objective C)dnl
])# AC_PROG_OBJC


# _AC_PROG_OBJC_G
# ---------------
# Check whether -g works, even if OBJCFLAGS is set, in case the package
# plays around with OBJCFLAGS (such as to build both debugging and
# normal versions of a library), tasteless as that idea is.
m4_define([_AC_PROG_OBJC_G],
[ac_test_OBJCFLAGS=${OBJCFLAGS+set}
ac_save_OBJCFLAGS=$OBJCFLAGS
OBJCFLAGS="-g"
AC_CACHE_CHECK(whether $OBJC accepts -g, ac_cv_prog_objc_g,
               [_AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
                                   [ac_cv_prog_objc_g=yes],
                                   [ac_cv_prog_objc_g=no])])
if test "$ac_test_OBJCFLAGS" = set; then
  OBJCFLAGS=$ac_save_OBJCFLAGS
elif test $ac_cv_prog_objc_g = yes; then
  if test "$GOBJC" = yes; then
    OBJCFLAGS="-g -O2"
  else
    OBJCFLAGS="-g"
  fi
else
  if test "$GOBJC" = yes; then
    OBJCFLAGS="-O2"
  else
    OBJCFLAGS=
  fi
fi[]dnl
])# _AC_PROG_OBJC_G


## ------------------------------- ##
## 4. Compilers' characteristics.  ##
## ------------------------------- ##


# -------------------------------- #
# 4b. C compiler characteristics.  #
# -------------------------------- #

# libobjc and objc header tests shere?