1# This file is part of Autoconf.			-*- Autoconf -*-
2# Programming languages support.
3# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Free Software
4# Foundation, Inc.
5#
6# This program is free software; you can redistribute it and/or modify
7# it under the terms of the GNU General Public License as published by
8# the Free Software Foundation; either version 2, or (at your option)
9# any later version.
10#
11# This program is distributed in the hope that it will be useful,
12# but WITHOUT ANY WARRANTY; without even the implied warranty of
13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14# GNU General Public License for more details.
15#
16# You should have received a copy of the GNU General Public License
17# along with this program; if not, write to the Free Software
18# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19# 02110-1301, USA.
20#
21# As a special exception, the Free Software Foundation gives unlimited
22# permission to copy, distribute and modify the configure scripts that
23# are the output of Autoconf.  You need not follow the terms of the GNU
24# General Public License when using or distributing such scripts, even
25# though portions of the text of Autoconf appear in them.  The GNU
26# General Public License (GPL) does govern all other use of the material
27# that constitutes the Autoconf program.
28#
29# Certain portions of the Autoconf source text are designed to be copied
30# (in certain cases, depending on the input) into the output of
31# Autoconf.  We call these the "data" portions.  The rest of the Autoconf
32# source text consists of comments plus executable code that decides which
33# of the data portions to output in any given case.  We call these
34# comments and executable code the "non-data" portions.  Autoconf never
35# copies any of the non-data portions into its output.
36#
37# This special exception to the GPL applies to versions of Autoconf
38# released by the Free Software Foundation.  When you make and
39# distribute a modified version of Autoconf, you may extend this special
40# exception to the GPL to apply to your modified version as well, *unless*
41# your modified version has the potential to copy into its output some
42# of the text that was the non-data portion of the version that you started
43# with.  (In other words, unless your change moves or copies text from
44# the non-data portions to the data portions.)  If your modification has
45# such potential, you must delete any notice of this special exception
46# to the GPL from your modified version.
47#
48# Written by David MacKenzie, with help from
49# Akim Demaille, Paul Eggert,
50# Franc,ois Pinard, Karl Berry, Richard Pixley, Ian Lance Taylor,
51# Roland McGrath, Noah Friedman, david d zuhn, and many others.
52
53
54# -------------------- #
55# 1b. The C language.  #
56# -------------------- #
57
58
59# AC_LANG(C)
60# ----------
61# CFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
62m4_define([AC_LANG(C)],
63[ac_ext=c
64ac_cpp='$CPP $CPPFLAGS'
65ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&AS_MESSAGE_LOG_FD'
66ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&AS_MESSAGE_LOG_FD'
67ac_compiler_gnu=$ac_cv_c_compiler_gnu
68])
69
70
71# AC_LANG_C
72# ---------
73AU_DEFUN([AC_LANG_C], [AC_LANG(C)])
74
75
76# _AC_LANG_ABBREV(C)
77# ------------------
78m4_define([_AC_LANG_ABBREV(C)], [c])
79
80
81# _AC_LANG_PREFIX(C)
82# ------------------
83m4_define([_AC_LANG_PREFIX(C)], [C])
84
85
86# ---------------------- #
87# 1c. The C++ language.  #
88# ---------------------- #
89
90
91# AC_LANG(C++)
92# ------------
93# CXXFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
94m4_define([AC_LANG(C++)],
95[ac_ext=cpp
96ac_cpp='$CXXCPP $CPPFLAGS'
97ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&AS_MESSAGE_LOG_FD'
98ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&AS_MESSAGE_LOG_FD'
99ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
100])
101
102
103# AC_LANG_CPLUSPLUS
104# -----------------
105AU_DEFUN([AC_LANG_CPLUSPLUS], [AC_LANG(C++)])
106
107
108# _AC_LANG_ABBREV(C++)
109# --------------------
110m4_define([_AC_LANG_ABBREV(C++)], [cxx])
111
112
113# _AC_LANG_PREFIX(C++)
114# --------------------
115m4_define([_AC_LANG_PREFIX(C++)], [CXX])
116
117
118
119# ------------------------------ #
120# 1d. The Objective C language.  #
121# ------------------------------ #
122
123
124# AC_LANG(Objective C)
125# --------------------
126m4_define([AC_LANG(Objective C)],
127[ac_ext=m
128ac_cpp='$OBJCPP $CPPFLAGS'
129ac_compile='$OBJC -c $OBJCFLAGS $CPPFLAGS conftest.$ac_ext >&AS_MESSAGE_LOG_FD'
130ac_link='$OBJC -o conftest$ac_exeext $OBJCFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&AS_MESSAGE_LOG_FD'
131ac_compiler_gnu=$ac_cv_objc_compiler_gnu
132])
133
134
135# AC_LANG_OBJC
136# ------------
137AU_DEFUN([AC_LANG_OBJC], [AC_LANG(Objective C)])
138
139
140# _AC_LANG_ABBREV(Objective C)
141# ----------------------------
142m4_define([_AC_LANG_ABBREV(Objective C)], [objc])
143
144
145# _AC_LANG_PREFIX(Objective C)
146# ----------------------------
147m4_define([_AC_LANG_PREFIX(Objective C)], [OBJC])
148
149
150
151## ---------------------- ##
152## 2.Producing programs.  ##
153## ---------------------- ##
154
155
156# --------------- #
157# 2b. C sources.  #
158# --------------- #
159
160# AC_LANG_SOURCE(C)(BODY)
161# -----------------------
162# We can't use '#line $LINENO "configure"' here, since
163# Sun c89 (Sun WorkShop 6 update 2 C 5.3 Patch 111679-08 2002/05/09)
164# rejects $LINENO greater than 32767, and some configure scripts
165# are longer than 32767 lines.
166m4_define([AC_LANG_SOURCE(C)],
167[/* confdefs.h.  */
168_ACEOF
169cat confdefs.h >>conftest.$ac_ext
170cat >>conftest.$ac_ext <<_ACEOF
171/* end confdefs.h.  */
172$1])
173
174
175# AC_LANG_PROGRAM(C)([PROLOGUE], [BODY])
176# --------------------------------------
177m4_define([AC_LANG_PROGRAM(C)],
178[$1
179m4_ifdef([_AC_LANG_PROGRAM_C_F77_HOOKS], [_AC_LANG_PROGRAM_C_F77_HOOKS])[]dnl
180m4_ifdef([_AC_LANG_PROGRAM_C_FC_HOOKS], [_AC_LANG_PROGRAM_C_FC_HOOKS])[]dnl
181int
182main ()
183{
184dnl Do *not* indent the following line: there may be CPP directives.
185dnl Don't move the `;' right after for the same reason.
186$2
187  ;
188  return 0;
189}])
190
191
192# AC_LANG_CALL(C)(PROLOGUE, FUNCTION)
193# -----------------------------------
194# Avoid conflicting decl of main.
195m4_define([AC_LANG_CALL(C)],
196[AC_LANG_PROGRAM([$1
197m4_if([$2], [main], ,
198[/* Override any GCC internal prototype to avoid an error.
199   Use char because int might match the return type of a GCC
200   builtin and then its argument prototype would still apply.  */
201#ifdef __cplusplus
202extern "C"
203#endif
204char $2 ();])], [return $2 ();])])
205
206
207# AC_LANG_FUNC_LINK_TRY(C)(FUNCTION)
208# ----------------------------------
209# Don't include <ctype.h> because on OSF/1 3.0 it includes
210# <sys/types.h> which includes <sys/select.h> which contains a
211# prototype for select.  Similarly for bzero.
212#
213# This test used to merely assign f=$1 in main(), but that was
214# optimized away by HP unbundled cc A.05.36 for ia64 under +O3,
215# presumably on the basis that there's no need to do that store if the
216# program is about to exit.  Conversely, the AIX linker optimizes an
217# unused external declaration that initializes f=$1.  So this test
218# program has both an external initialization of f, and a use of f in
219# main that affects the exit status.
220#
221m4_define([AC_LANG_FUNC_LINK_TRY(C)],
222[AC_LANG_PROGRAM(
223[/* Define $1 to an innocuous variant, in case <limits.h> declares $1.
224   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
225#define $1 innocuous_$1
226
227/* System header to define __stub macros and hopefully few prototypes,
228    which can conflict with char $1 (); below.
229    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
230    <limits.h> exists even on freestanding compilers.  */
231
232#ifdef __STDC__
233# include <limits.h>
234#else
235# include <assert.h>
236#endif
237
238#undef $1
239
240/* Override any GCC internal prototype to avoid an error.
241   Use char because int might match the return type of a GCC
242   builtin and then its argument prototype would still apply.  */
243#ifdef __cplusplus
244extern "C"
245#endif
246char $1 ();
247/* The GNU C library defines this for functions which it implements
248    to always fail with ENOSYS.  Some functions are actually named
249    something starting with __ and the normal name is an alias.  */
250#if defined __stub_$1 || defined __stub___$1
251choke me
252#endif
253], [return $1 ();])])
254
255
256# AC_LANG_BOOL_COMPILE_TRY(C)(PROLOGUE, EXPRESSION)
257# -------------------------------------------------
258# Return a program that is valid if EXPRESSION is nonzero.
259# EXPRESSION must be an integer constant expression.
260# Be sure to use this array to avoid `unused' warnings, which are even
261# errors with `-W error'.
262m4_define([AC_LANG_BOOL_COMPILE_TRY(C)],
263[AC_LANG_PROGRAM([$1], [static int test_array @<:@1 - 2 * !($2)@:>@;
264test_array @<:@0@:>@ = 0
265])])
266
267
268# AC_LANG_INT_SAVE(C)(PROLOGUE, EXPRESSION)
269# -----------------------------------------
270# We need `stdio.h' to open a `FILE' and `stdlib.h' for `exit'.
271# But we include them only after the EXPRESSION has been evaluated.
272m4_define([AC_LANG_INT_SAVE(C)],
273[AC_LANG_PROGRAM([$1
274static long int longval () { return $2; }
275static unsigned long int ulongval () { return $2; }
276@%:@include <stdio.h>
277@%:@include <stdlib.h>],
278[
279  FILE *f = fopen ("conftest.val", "w");
280  if (! f)
281    return 1;
282  if (($2) < 0)
283    {
284      long int i = longval ();
285      if (i != ($2))
286	return 1;
287      fprintf (f, "%ld\n", i);
288    }
289  else
290    {
291      unsigned long int i = ulongval ();
292      if (i != ($2))
293	return 1;
294      fprintf (f, "%lu\n", i);
295    }
296  return ferror (f) || fclose (f) != 0;
297])])
298
299
300# ----------------- #
301# 2c. C++ sources.  #
302# ----------------- #
303
304# AC_LANG_SOURCE(C++)(BODY)
305# -------------------------
306m4_copy([AC_LANG_SOURCE(C)], [AC_LANG_SOURCE(C++)])
307
308
309# AC_LANG_PROGRAM(C++)([PROLOGUE], [BODY])
310# ----------------------------------------
311m4_copy([AC_LANG_PROGRAM(C)], [AC_LANG_PROGRAM(C++)])
312
313
314# AC_LANG_CALL(C++)(PROLOGUE, FUNCTION)
315# -------------------------------------
316m4_copy([AC_LANG_CALL(C)], [AC_LANG_CALL(C++)])
317
318
319# AC_LANG_FUNC_LINK_TRY(C++)(FUNCTION)
320# ------------------------------------
321m4_copy([AC_LANG_FUNC_LINK_TRY(C)], [AC_LANG_FUNC_LINK_TRY(C++)])
322
323
324# AC_LANG_BOOL_COMPILE_TRY(C++)(PROLOGUE, EXPRESSION)
325# ---------------------------------------------------
326m4_copy([AC_LANG_BOOL_COMPILE_TRY(C)], [AC_LANG_BOOL_COMPILE_TRY(C++)])
327
328
329# AC_LANG_INT_SAVE(C++)(PROLOGUE, EXPRESSION)
330# -------------------------------------------
331m4_copy([AC_LANG_INT_SAVE(C)], [AC_LANG_INT_SAVE(C++)])
332
333
334
335# ------------------------- #
336# 2d. Objective C sources.  #
337# ------------------------- #
338
339# AC_LANG_SOURCE(Objective C)(BODY)
340# ---------------------------------
341m4_copy([AC_LANG_SOURCE(C)], [AC_LANG_SOURCE(Objective C)])
342
343
344# AC_LANG_PROGRAM(Objective C)([PROLOGUE], [BODY])
345# ------------------------------------------------
346m4_copy([AC_LANG_PROGRAM(C)], [AC_LANG_PROGRAM(Objective C)])
347
348
349# AC_LANG_CALL(Objective C)(PROLOGUE, FUNCTION)
350# ---------------------------------------------
351m4_copy([AC_LANG_CALL(C)], [AC_LANG_CALL(Objective C)])
352
353
354# AC_LANG_FUNC_LINK_TRY(Objective C)(FUNCTION)
355# --------------------------------------------
356m4_copy([AC_LANG_FUNC_LINK_TRY(C)], [AC_LANG_FUNC_LINK_TRY(Objective C)])
357
358
359# AC_LANG_BOOL_COMPILE_TRY(Objective C)(PROLOGUE, EXPRESSION)
360# -----------------------------------------------------------
361m4_copy([AC_LANG_BOOL_COMPILE_TRY(C)], [AC_LANG_BOOL_COMPILE_TRY(Objective C)])
362
363
364# AC_LANG_INT_SAVE(Objective C)(PROLOGUE, EXPRESSION)
365# ---------------------------------------------------
366m4_copy([AC_LANG_INT_SAVE(C)], [AC_LANG_INT_SAVE(Objective C)])
367
368
369
370## -------------------------------------------- ##
371## 3. Looking for Compilers and Preprocessors.  ##
372## -------------------------------------------- ##
373
374# -------------------- #
375# 3b. The C compiler.  #
376# -------------------- #
377
378
379# _AC_ARG_VAR_CPPFLAGS
380# --------------------
381# Document and register CPPFLAGS, which is used by
382# AC_PROG_{CC, CPP, CXX, CXXCPP, OBJC, OBJCPP}.
383AC_DEFUN([_AC_ARG_VAR_CPPFLAGS],
384[AC_ARG_VAR([CPPFLAGS],
385	    [C/C++/Objective C preprocessor flags, e.g. -I<include dir>
386	     if you have headers in a nonstandard directory <include dir>])])
387
388
389# _AC_ARG_VAR_LDFLAGS
390# -------------------
391# Document and register LDFLAGS, which is used by
392# AC_PROG_{CC, CXX, F77, FC, OBJC}.
393AC_DEFUN([_AC_ARG_VAR_LDFLAGS],
394[AC_ARG_VAR([LDFLAGS],
395	    [linker flags, e.g. -L<lib dir> if you have libraries in a
396	     nonstandard directory <lib dir>])])
397
398
399# _AC_ARG_VAR_LIBS
400# ----------------
401# Document and register LIBS, which is used by
402# AC_PROG_{CC, CXX, F77, FC, OBJS}.
403AC_DEFUN([_AC_ARG_VAR_LIBS],
404[AC_ARG_VAR([LIBS],
405	    [libraries to pass to the linker, e.g. -l<library>])])
406
407
408# AC_LANG_PREPROC(C)
409# -------------------
410# Find the C preprocessor.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
411AC_DEFUN([AC_LANG_PREPROC(C)],
412[AC_REQUIRE([AC_PROG_CPP])])
413
414
415# _AC_PROG_PREPROC_WORKS_IFELSE(IF-WORKS, IF-NOT)
416# -----------------------------------------------
417# Check if $ac_cpp is a working preprocessor that can flag absent
418# includes either by the exit status or by warnings.
419# This macro is for all languages, not only C.
420AC_DEFUN([_AC_PROG_PREPROC_WORKS_IFELSE],
421[ac_preproc_ok=false
422for ac_[]_AC_LANG_ABBREV[]_preproc_warn_flag in '' yes
423do
424  # Use a header file that comes with gcc, so configuring glibc
425  # with a fresh cross-compiler works.
426  # Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
427  # <limits.h> exists even on freestanding compilers.
428  # On the NeXT, cc -E runs the code through the compiler's parser,
429  # not just through cpp. "Syntax error" is here to catch this case.
430  _AC_PREPROC_IFELSE([AC_LANG_SOURCE([[@%:@ifdef __STDC__
431@%:@ include <limits.h>
432@%:@else
433@%:@ include <assert.h>
434@%:@endif
435		     Syntax error]])],
436		     [],
437		     [# Broken: fails on valid input.
438continue])
439
440  # OK, works on sane cases.  Now check whether nonexistent headers
441  # can be detected and how.
442  _AC_PREPROC_IFELSE([AC_LANG_SOURCE([[@%:@include <ac_nonexistent.h>]])],
443		     [# Broken: success on invalid input.
444continue],
445		     [# Passes both tests.
446ac_preproc_ok=:
447break])
448
449done
450# Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
451rm -f conftest.err conftest.$ac_ext
452AS_IF([$ac_preproc_ok], [$1], [$2])])# _AC_PROG_PREPROC_WORKS_IFELSE
453
454
455# AC_PROG_CPP
456# -----------
457# Find a working C preprocessor.
458# We shouldn't have to require AC_PROG_CC, but this is due to the concurrency
459# between the AC_LANG_COMPILER_REQUIRE family and that of AC_PROG_CC.
460AN_MAKEVAR([CPP], [AC_PROG_CPP])
461AN_PROGRAM([cpp], [AC_PROG_CPP])
462AC_DEFUN([AC_PROG_CPP],
463[AC_REQUIRE([AC_PROG_CC])dnl
464AC_ARG_VAR([CPP],      [C preprocessor])dnl
465_AC_ARG_VAR_CPPFLAGS()dnl
466AC_LANG_PUSH(C)dnl
467AC_MSG_CHECKING([how to run the C preprocessor])
468# On Suns, sometimes $CPP names a directory.
469if test -n "$CPP" && test -d "$CPP"; then
470  CPP=
471fi
472if test -z "$CPP"; then
473  AC_CACHE_VAL([ac_cv_prog_CPP],
474  [dnl
475    # Double quotes because CPP needs to be expanded
476    for CPP in "$CC -E" "$CC -E -traditional-cpp" "/lib/cpp"
477    do
478      _AC_PROG_PREPROC_WORKS_IFELSE([break])
479    done
480    ac_cv_prog_CPP=$CPP
481  ])dnl
482  CPP=$ac_cv_prog_CPP
483else
484  ac_cv_prog_CPP=$CPP
485fi
486AC_MSG_RESULT([$CPP])
487_AC_PROG_PREPROC_WORKS_IFELSE([],
488		[AC_MSG_FAILURE([C preprocessor "$CPP" fails sanity check])])
489AC_SUBST(CPP)dnl
490AC_LANG_POP(C)dnl
491])# AC_PROG_CPP
492
493# AC_PROG_CPP_WERROR
494# ------------------
495# Treat warnings from the preprocessor as errors.
496AC_DEFUN([AC_PROG_CPP_WERROR],
497[AC_REQUIRE([AC_PROG_CPP])dnl
498ac_c_preproc_warn_flag=yes])# AC_PROG_CPP_WERROR
499
500# AC_LANG_COMPILER(C)
501# -------------------
502# Find the C compiler.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
503AC_DEFUN([AC_LANG_COMPILER(C)],
504[AC_REQUIRE([AC_PROG_CC])])
505
506
507# ac_cv_prog_gcc
508# --------------
509# We used to name the cache variable this way.
510AU_DEFUN([ac_cv_prog_gcc],
511[ac_cv_c_compiler_gnu])
512
513
514# AC_PROG_CC([COMPILER ...])
515# --------------------------
516# COMPILER ... is a space separated list of C compilers to search for.
517# This just gives the user an opportunity to specify an alternative
518# search list for the C compiler.
519AN_MAKEVAR([CC],  [AC_PROG_CC])
520AN_PROGRAM([cc],  [AC_PROG_CC])
521AN_PROGRAM([gcc], [AC_PROG_CC])
522AC_DEFUN([AC_PROG_CC],
523[AC_LANG_PUSH(C)dnl
524AC_ARG_VAR([CC],     [C compiler command])dnl
525AC_ARG_VAR([CFLAGS], [C compiler flags])dnl
526_AC_ARG_VAR_LDFLAGS()dnl
527_AC_ARG_VAR_LIBS()dnl
528_AC_ARG_VAR_CPPFLAGS()dnl
529m4_ifval([$1],
530      [AC_CHECK_TOOLS(CC, [$1])],
531[AC_CHECK_TOOL(CC, gcc)
532if test -z "$CC"; then
533  dnl Here we want:
534  dnl	AC_CHECK_TOOL(CC, cc)
535  dnl but without the check for a tool without the prefix.
536  dnl Until the check is removed from there, copy the code:
537  if test -n "$ac_tool_prefix"; then
538    AC_CHECK_PROG(CC, [${ac_tool_prefix}cc], [${ac_tool_prefix}cc])
539  fi
540fi
541if test -z "$CC"; then
542  AC_CHECK_PROG(CC, cc, cc, , , /usr/ucb/cc)
543fi
544if test -z "$CC"; then
545  AC_CHECK_TOOLS(CC, cl.exe)
546fi
547])
548
549test -z "$CC" && AC_MSG_FAILURE([no acceptable C compiler found in \$PATH])
550
551# Provide some information about the compiler.
552_AS_ECHO_LOG([checking for _AC_LANG compiler version])
553ac_compiler=`set X $ac_compile; echo $[2]`
554_AC_DO([$ac_compiler --version >&AS_MESSAGE_LOG_FD])
555_AC_DO([$ac_compiler -v >&AS_MESSAGE_LOG_FD])
556_AC_DO([$ac_compiler -V >&AS_MESSAGE_LOG_FD])
557
558m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
559m4_expand_once([_AC_COMPILER_OBJEXT])[]dnl
560_AC_LANG_COMPILER_GNU
561GCC=`test $ac_compiler_gnu = yes && echo yes`
562_AC_PROG_CC_G
563_AC_PROG_CC_C89
564AC_LANG_POP(C)dnl
565])# AC_PROG_CC
566
567
568# _AC_PROG_CC_G
569# -------------
570# Check whether -g works, even if CFLAGS is set, in case the package
571# plays around with CFLAGS (such as to build both debugging and normal
572# versions of a library), tasteless as that idea is.
573# Don't consider -g to work if it generates warnings when plain compiles don't.
574m4_define([_AC_PROG_CC_G],
575[ac_test_CFLAGS=${CFLAGS+set}
576ac_save_CFLAGS=$CFLAGS
577AC_CACHE_CHECK(whether $CC accepts -g, ac_cv_prog_cc_g,
578  [ac_save_c_werror_flag=$ac_c_werror_flag
579   ac_c_werror_flag=yes
580   ac_cv_prog_cc_g=no
581   CFLAGS="-g"
582   _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
583     [ac_cv_prog_cc_g=yes],
584     [CFLAGS=""
585      _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
586	[],
587	[ac_c_werror_flag=$ac_save_c_werror_flag
588	 CFLAGS="-g"
589	 _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
590	   [ac_cv_prog_cc_g=yes])])])
591   ac_c_werror_flag=$ac_save_c_werror_flag])
592if test "$ac_test_CFLAGS" = set; then
593  CFLAGS=$ac_save_CFLAGS
594elif test $ac_cv_prog_cc_g = yes; then
595  if test "$GCC" = yes; then
596    CFLAGS="-g -O2"
597  else
598    CFLAGS="-g"
599  fi
600else
601  if test "$GCC" = yes; then
602    CFLAGS="-O2"
603  else
604    CFLAGS=
605  fi
606fi[]dnl
607])# _AC_PROG_CC_G
608
609
610# AC_PROG_GCC_TRADITIONAL
611# -----------------------
612AN_FUNCTION([ioctl],   [AC_PROG_GCC_TRADITIONAL])
613AC_DEFUN([AC_PROG_GCC_TRADITIONAL],
614[AC_REQUIRE([AC_PROG_CC])dnl
615if test $ac_cv_c_compiler_gnu = yes; then
616    AC_CACHE_CHECK(whether $CC needs -traditional,
617      ac_cv_prog_gcc_traditional,
618[  ac_pattern="Autoconf.*'x'"
619  AC_EGREP_CPP($ac_pattern, [#include <sgtty.h>
620Autoconf TIOCGETP],
621  ac_cv_prog_gcc_traditional=yes, ac_cv_prog_gcc_traditional=no)
622
623  if test $ac_cv_prog_gcc_traditional = no; then
624    AC_EGREP_CPP($ac_pattern, [#include <termio.h>
625Autoconf TCGETA],
626    ac_cv_prog_gcc_traditional=yes)
627  fi])
628  if test $ac_cv_prog_gcc_traditional = yes; then
629    CC="$CC -traditional"
630  fi
631fi
632])# AC_PROG_GCC_TRADITIONAL
633
634
635# AC_PROG_CC_C_O
636# --------------
637AC_DEFUN([AC_PROG_CC_C_O],
638[AC_REQUIRE([AC_PROG_CC])dnl
639if test "x$CC" != xcc; then
640  AC_MSG_CHECKING([whether $CC and cc understand -c and -o together])
641else
642  AC_MSG_CHECKING([whether cc understands -c and -o together])
643fi
644set dummy $CC; ac_cc=`echo $[2] |
645		      sed 's/[[^a-zA-Z0-9_]]/_/g;s/^[[0-9]]/_/'`
646AC_CACHE_VAL(ac_cv_prog_cc_${ac_cc}_c_o,
647[AC_LANG_CONFTEST([AC_LANG_PROGRAM([])])
648# Make sure it works both with $CC and with simple cc.
649# We do the test twice because some compilers refuse to overwrite an
650# existing .o file with -o, though they will create one.
651ac_try='$CC -c conftest.$ac_ext -o conftest2.$ac_objext >&AS_MESSAGE_LOG_FD'
652rm -f conftest2.*
653if _AC_DO_VAR(ac_try) &&
654   test -f conftest2.$ac_objext && _AC_DO_VAR(ac_try);
655then
656  eval ac_cv_prog_cc_${ac_cc}_c_o=yes
657  if test "x$CC" != xcc; then
658    # Test first that cc exists at all.
659    if _AC_DO_TOKENS(cc -c conftest.$ac_ext >&AS_MESSAGE_LOG_FD); then
660      ac_try='cc -c conftest.$ac_ext -o conftest2.$ac_objext >&AS_MESSAGE_LOG_FD'
661      rm -f conftest2.*
662      if _AC_DO_VAR(ac_try) &&
663	 test -f conftest2.$ac_objext && _AC_DO_VAR(ac_try);
664      then
665	# cc works too.
666	:
667      else
668	# cc exists but doesn't like -o.
669	eval ac_cv_prog_cc_${ac_cc}_c_o=no
670      fi
671    fi
672  fi
673else
674  eval ac_cv_prog_cc_${ac_cc}_c_o=no
675fi
676rm -f core conftest*
677])dnl
678if eval test \$ac_cv_prog_cc_${ac_cc}_c_o = yes; then
679  AC_MSG_RESULT([yes])
680else
681  AC_MSG_RESULT([no])
682  AC_DEFINE(NO_MINUS_C_MINUS_O, 1,
683	   [Define to 1 if your C compiler doesn't accept -c and -o together.])
684fi
685])# AC_PROG_CC_C_O
686
687
688# ---------------------- #
689# 3c. The C++ compiler.  #
690# ---------------------- #
691
692
693# AC_LANG_PREPROC(C++)
694# ---------------------
695# Find the C++ preprocessor.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
696AC_DEFUN([AC_LANG_PREPROC(C++)],
697[AC_REQUIRE([AC_PROG_CXXCPP])])
698
699
700# AC_PROG_CXXCPP
701# --------------
702# Find a working C++ preprocessor.
703# We shouldn't have to require AC_PROG_CC, but this is due to the concurrency
704# between the AC_LANG_COMPILER_REQUIRE family and that of AC_PROG_CXX.
705AC_DEFUN([AC_PROG_CXXCPP],
706[AC_REQUIRE([AC_PROG_CXX])dnl
707AC_ARG_VAR([CXXCPP],   [C++ preprocessor])dnl
708_AC_ARG_VAR_CPPFLAGS()dnl
709AC_LANG_PUSH(C++)dnl
710AC_MSG_CHECKING([how to run the C++ preprocessor])
711if test -z "$CXXCPP"; then
712  AC_CACHE_VAL(ac_cv_prog_CXXCPP,
713  [dnl
714    # Double quotes because CXXCPP needs to be expanded
715    for CXXCPP in "$CXX -E" "/lib/cpp"
716    do
717      _AC_PROG_PREPROC_WORKS_IFELSE([break])
718    done
719    ac_cv_prog_CXXCPP=$CXXCPP
720  ])dnl
721  CXXCPP=$ac_cv_prog_CXXCPP
722else
723  ac_cv_prog_CXXCPP=$CXXCPP
724fi
725AC_MSG_RESULT([$CXXCPP])
726_AC_PROG_PREPROC_WORKS_IFELSE([],
727	  [AC_MSG_FAILURE([C++ preprocessor "$CXXCPP" fails sanity check])])
728AC_SUBST(CXXCPP)dnl
729AC_LANG_POP(C++)dnl
730])# AC_PROG_CXXCPP
731
732
733# AC_LANG_COMPILER(C++)
734# ---------------------
735# Find the C++ compiler.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
736AC_DEFUN([AC_LANG_COMPILER(C++)],
737[AC_REQUIRE([AC_PROG_CXX])])
738
739
740# ac_cv_prog_gxx
741# --------------
742# We used to name the cache variable this way.
743AU_DEFUN([ac_cv_prog_gxx],
744[ac_cv_cxx_compiler_gnu])
745
746
747# AC_PROG_CXX([LIST-OF-COMPILERS])
748# --------------------------------
749# LIST-OF-COMPILERS is a space separated list of C++ compilers to search
750# for (if not specified, a default list is used).  This just gives the
751# user an opportunity to specify an alternative search list for the C++
752# compiler.
753# aCC	HP-UX C++ compiler much better than `CC', so test before.
754# FCC   Fujitsu C++ compiler
755# KCC	KAI C++ compiler
756# RCC	Rational C++
757# xlC_r	AIX C Set++ (with support for reentrant code)
758# xlC	AIX C Set++
759AN_MAKEVAR([CXX],  [AC_PROG_CXX])
760AN_PROGRAM([CC],   [AC_PROG_CXX])
761AN_PROGRAM([c++],  [AC_PROG_CXX])
762AN_PROGRAM([g++],  [AC_PROG_CXX])
763AC_DEFUN([AC_PROG_CXX],
764[AC_LANG_PUSH(C++)dnl
765AC_ARG_VAR([CXX],      [C++ compiler command])dnl
766AC_ARG_VAR([CXXFLAGS], [C++ compiler flags])dnl
767_AC_ARG_VAR_LDFLAGS()dnl
768_AC_ARG_VAR_LIBS()dnl
769_AC_ARG_VAR_CPPFLAGS()dnl
770_AC_ARG_VAR_PRECIOUS([CCC])dnl
771if test -z "$CXX"; then
772  if test -n "$CCC"; then
773    CXX=$CCC
774  else
775    AC_CHECK_TOOLS(CXX,
776		   [m4_default([$1],
777			       [g++ c++ gpp aCC CC cxx cc++ cl.exe FCC KCC RCC xlC_r xlC])],
778		   g++)
779  fi
780fi
781# Provide some information about the compiler.
782_AS_ECHO_LOG([checking for _AC_LANG compiler version])
783ac_compiler=`set X $ac_compile; echo $[2]`
784_AC_DO([$ac_compiler --version >&AS_MESSAGE_LOG_FD])
785_AC_DO([$ac_compiler -v >&AS_MESSAGE_LOG_FD])
786_AC_DO([$ac_compiler -V >&AS_MESSAGE_LOG_FD])
787
788m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
789m4_expand_once([_AC_COMPILER_OBJEXT])[]dnl
790_AC_LANG_COMPILER_GNU
791GXX=`test $ac_compiler_gnu = yes && echo yes`
792_AC_PROG_CXX_G
793AC_LANG_POP(C++)dnl
794])# AC_PROG_CXX
795
796
797# _AC_PROG_CXX_G
798# --------------
799# Check whether -g works, even if CXXFLAGS is set, in case the package
800# plays around with CXXFLAGS (such as to build both debugging and
801# normal versions of a library), tasteless as that idea is.
802# Don't consider -g to work if it generates warnings when plain compiles don't.
803m4_define([_AC_PROG_CXX_G],
804[ac_test_CXXFLAGS=${CXXFLAGS+set}
805ac_save_CXXFLAGS=$CXXFLAGS
806AC_CACHE_CHECK(whether $CXX accepts -g, ac_cv_prog_cxx_g,
807  [ac_save_cxx_werror_flag=$ac_cxx_werror_flag
808   ac_cxx_werror_flag=yes
809   ac_cv_prog_cxx_g=no
810   CXXFLAGS="-g"
811   _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
812     [ac_cv_prog_cxx_g=yes],
813     [CXXFLAGS=""
814      _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
815	[],
816	[ac_cxx_werror_flag=$ac_save_cxx_werror_flag
817	 CXXFLAGS="-g"
818	 _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
819	   [ac_cv_prog_cxx_g=yes])])])
820   ac_cxx_werror_flag=$ac_save_cxx_werror_flag])
821if test "$ac_test_CXXFLAGS" = set; then
822  CXXFLAGS=$ac_save_CXXFLAGS
823elif test $ac_cv_prog_cxx_g = yes; then
824  if test "$GXX" = yes; then
825    CXXFLAGS="-g -O2"
826  else
827    CXXFLAGS="-g"
828  fi
829else
830  if test "$GXX" = yes; then
831    CXXFLAGS="-O2"
832  else
833    CXXFLAGS=
834  fi
835fi[]dnl
836])# _AC_PROG_CXX_G
837
838
839# AC_PROG_CXX_C_O
840# ---------------
841# Test if the C++ compiler accepts the options `-c' and `-o'
842# simultaneously, and define `CXX_NO_MINUS_C_MINUS_O' if it does not.
843AC_DEFUN([AC_PROG_CXX_C_O],
844[AC_REQUIRE([AC_PROG_CXX])dnl
845AC_LANG_PUSH([C++])dnl
846AC_CACHE_CHECK([whether $CXX understands -c and -o together],
847               [ac_cv_prog_cxx_c_o],
848[AC_LANG_CONFTEST([AC_LANG_PROGRAM([])])
849# We test twice because some compilers refuse to overwrite an existing
850# `.o' file with `-o', although they will create one.
851ac_try='$CXX $CXXFLAGS -c conftest.$ac_ext -o conftest2.$ac_objext >&AS_MESSAGE_LOG_FD'
852rm -f conftest2.*
853if _AC_DO_VAR(ac_try) &&
854     test -f conftest2.$ac_objext &&
855     _AC_DO_VAR(ac_try); then
856  ac_cv_prog_cxx_c_o=yes
857else
858  ac_cv_prog_cxx_c_o=no
859fi
860rm -f conftest*])
861if test $ac_cv_prog_cxx_c_o = no; then
862  AC_DEFINE(CXX_NO_MINUS_C_MINUS_O, 1,
863            [Define to 1 if your C++ compiler doesn't accept
864             -c and -o together.])
865fi
866AC_LANG_POP([C++])dnl
867])# AC_PROG_CXX_C_O
868
869
870# ------------------------------ #
871# 3d. The Objective C compiler.  #
872# ------------------------------ #
873
874
875# AC_LANG_PREPROC(Objective C)
876# ----------------------------
877# Find the Objective C preprocessor.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
878AC_DEFUN([AC_LANG_PREPROC(Objective C)],
879[AC_REQUIRE([AC_PROG_OBJCPP])])
880
881
882# AC_PROG_OBJCPP
883# --------------
884# Find a working Objective C preprocessor.
885AC_DEFUN([AC_PROG_OBJCPP],
886[AC_REQUIRE([AC_PROG_OBJC])dnl
887AC_ARG_VAR([OBJCPP],   [Objective C preprocessor])dnl
888_AC_ARG_VAR_CPPFLAGS()dnl
889AC_LANG_PUSH(Objective C)dnl
890AC_MSG_CHECKING([how to run the Objective C preprocessor])
891if test -z "$OBJCPP"; then
892  AC_CACHE_VAL(ac_cv_prog_OBJCPP,
893  [dnl
894    # Double quotes because OBJCPP needs to be expanded
895    for OBJCPP in "$OBJC -E" "/lib/cpp"
896    do
897      _AC_PROG_PREPROC_WORKS_IFELSE([break])
898    done
899    ac_cv_prog_OBJCPP=$OBJCPP
900  ])dnl
901  OBJCPP=$ac_cv_prog_OBJCPP
902else
903  ac_cv_prog_OBJCPP=$OBJCPP
904fi
905AC_MSG_RESULT([$OBJCPP])
906_AC_PROG_PREPROC_WORKS_IFELSE([],
907	  [AC_MSG_FAILURE([Objective C preprocessor "$OBJCPP" fails sanity check])])
908AC_SUBST(OBJCPP)dnl
909AC_LANG_POP(Objective C)dnl
910])# AC_PROG_OBJCPP
911
912
913# AC_LANG_COMPILER(Objective C)
914# -----------------------------
915# Find the Objective C compiler.  Must be AC_DEFUN'd to be AC_REQUIRE'able.
916AC_DEFUN([AC_LANG_COMPILER(Objective C)],
917[AC_REQUIRE([AC_PROG_OBJC])])
918
919
920
921# AC_PROG_OBJC([LIST-OF-COMPILERS])
922# ---------------------------------
923# LIST-OF-COMPILERS is a space separated list of Objective C compilers to
924# search for (if not specified, a default list is used).  This just gives
925# the user an opportunity to specify an alternative search list for the
926# Objective C compiler.
927# objcc StepStone Objective-C compiler (also "standard" name for OBJC)
928# objc  David Stes' POC.  If you installed this, you likely want it.
929# cc    Native C compiler (for instance, Apple).
930# CC    You never know.
931AN_MAKEVAR([OBJC],  [AC_PROG_OBJC])
932AN_PROGRAM([objcc],  [AC_PROG_OBJC])
933AN_PROGRAM([objc],  [AC_PROG_OBJC])
934AC_DEFUN([AC_PROG_OBJC],
935[AC_LANG_PUSH(Objective C)dnl
936AC_ARG_VAR([OBJC],      [Objective C compiler command])dnl
937AC_ARG_VAR([OBJCFLAGS], [Objective C compiler flags])dnl
938_AC_ARG_VAR_LDFLAGS()dnl
939_AC_ARG_VAR_LIBS()dnl
940_AC_ARG_VAR_CPPFLAGS()dnl
941_AC_ARG_VAR_PRECIOUS([OBJC])dnl
942AC_CHECK_TOOLS(OBJC,
943	       [m4_default([$1], [gcc objcc objc cc CC])],
944	       gcc)
945# Provide some information about the compiler.
946_AS_ECHO_LOG([checking for _AC_LANG compiler version])
947ac_compiler=`set X $ac_compile; echo $[2]`
948_AC_DO([$ac_compiler --version >&AS_MESSAGE_LOG_FD])
949_AC_DO([$ac_compiler -v >&AS_MESSAGE_LOG_FD])
950_AC_DO([$ac_compiler -V >&AS_MESSAGE_LOG_FD])
951
952m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
953m4_expand_once([_AC_COMPILER_OBJEXT])[]dnl
954_AC_LANG_COMPILER_GNU
955GOBJC=`test $ac_compiler_gnu = yes && echo yes`
956_AC_PROG_OBJC_G
957AC_LANG_POP(Objective C)dnl
958])# AC_PROG_OBJC
959
960
961# _AC_PROG_OBJC_G
962# ---------------
963# Check whether -g works, even if OBJCFLAGS is set, in case the package
964# plays around with OBJCFLAGS (such as to build both debugging and
965# normal versions of a library), tasteless as that idea is.
966# Don't consider -g to work if it generates warnings when plain compiles don't.
967m4_define([_AC_PROG_OBJC_G],
968[ac_test_OBJCFLAGS=${OBJCFLAGS+set}
969ac_save_OBJCFLAGS=$OBJCFLAGS
970AC_CACHE_CHECK(whether $OBJC accepts -g, ac_cv_prog_objc_g,
971  [ac_save_objc_werror_flag=$ac_objc_werror_flag
972   ac_objc_werror_flag=yes
973   ac_cv_prog_objc_g=no
974   OBJCFLAGS="-g"
975   _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
976     [ac_cv_prog_objc_g=yes],
977     [OBJCFLAGS=""
978      _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
979	[],
980	[ac_objc_werror_flag=$ac_save_objc_werror_flag
981	 OBJCFLAGS="-g"
982	 _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
983	   [ac_cv_prog_objc_g=yes])])])
984   ac_objc_werror_flag=$ac_save_objc_werror_flag])
985if test "$ac_test_OBJCFLAGS" = set; then
986  OBJCFLAGS=$ac_save_OBJCFLAGS
987elif test $ac_cv_prog_objc_g = yes; then
988  if test "$GOBJC" = yes; then
989    OBJCFLAGS="-g -O2"
990  else
991    OBJCFLAGS="-g"
992  fi
993else
994  if test "$GOBJC" = yes; then
995    OBJCFLAGS="-O2"
996  else
997    OBJCFLAGS=
998  fi
999fi[]dnl
1000])# _AC_PROG_OBJC_G
1001
1002
1003
1004
1005
1006
1007## ------------------------------- ##
1008## 4. Compilers' characteristics.  ##
1009## ------------------------------- ##
1010
1011
1012# -------------------------------- #
1013# 4b. C compiler characteristics.  #
1014# -------------------------------- #
1015
1016# _AC_PROG_CC_C89 ([ACTION-IF-AVAILABLE], [ACTION-IF-UNAVAILABLE])
1017# ----------------------------------------------------------------
1018# If the C compiler is not in ANSI C89 (ISO C90) mode by default, try
1019# to add an option to output variable CC to make it so.  This macro
1020# tries various options that select ANSI C89 on some system or
1021# another.  It considers the compiler to be in ANSI C89 mode if it
1022# handles function prototypes correctly.
1023AC_DEFUN([_AC_PROG_CC_C89],
1024[_AC_C_STD_TRY([c89],
1025[[#include <stdarg.h>
1026#include <stdio.h>
1027#include <sys/types.h>
1028#include <sys/stat.h>
1029/* Most of the following tests are stolen from RCS 5.7's src/conf.sh.  */
1030struct buf { int x; };
1031FILE * (*rcsopen) (struct buf *, struct stat *, int);
1032static char *e (p, i)
1033     char **p;
1034     int i;
1035{
1036  return p[i];
1037}
1038static char *f (char * (*g) (char **, int), char **p, ...)
1039{
1040  char *s;
1041  va_list v;
1042  va_start (v,p);
1043  s = g (p, va_arg (v,int));
1044  va_end (v);
1045  return s;
1046}
1047
1048/* OSF 4.0 Compaq cc is some sort of almost-ANSI by default.  It has
1049   function prototypes and stuff, but not '\xHH' hex character constants.
1050   These don't provoke an error unfortunately, instead are silently treated
1051   as 'x'.  The following induces an error, until -std is added to get
1052   proper ANSI mode.  Curiously '\x00'!='x' always comes out true, for an
1053   array size at least.  It's necessary to write '\x00'==0 to get something
1054   that's true only with -std.  */
1055int osf4_cc_array ['\x00' == 0 ? 1 : -1];
1056
1057/* IBM C 6 for AIX is almost-ANSI by default, but it replaces macro parameters
1058   inside strings and character constants.  */
1059#define FOO(x) 'x'
1060int xlc6_cc_array[FOO(a) == 'x' ? 1 : -1];
1061
1062int test (int i, double x);
1063struct s1 {int (*f) (int a);};
1064struct s2 {int (*f) (double a);};
1065int pairnames (int, char **, FILE *(*)(struct buf *, struct stat *, int), int, int);
1066int argc;
1067char **argv;]],
1068[[return f (e, argv, 0) != argv[0]  ||  f (e, argv, 1) != argv[1];]],
1069dnl Don't try gcc -ansi; that turns off useful extensions and
1070dnl breaks some systems' header files.
1071dnl AIX circa 2003	-qlanglvl=extc89
1072dnl old AIX		-qlanglvl=ansi
1073dnl Ultrix, OSF/1, Tru64	-std
1074dnl HP-UX 10.20 and later	-Ae
1075dnl HP-UX older versions	-Aa -D_HPUX_SOURCE
1076dnl SVR4			-Xc -D__EXTENSIONS__
1077[-qlanglvl=extc89 -qlanglvl=ansi -std \
1078	-Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"], [$1], [$2])[]dnl
1079])# _AC_PROG_CC_C89
1080
1081
1082# _AC_C_STD_TRY(STANDARD, TEST-PROLOGUE, TEST-BODY, OPTION-LIST,
1083#		ACTION-IF-AVAILABLE, ACTION-IF-UNAVAILABLE)
1084# --------------------------------------------------------------
1085# Check whether the C compiler accepts features of STANDARD (e.g `c89', `c99')
1086# by trying to compile a program of TEST-PROLOGUE and TEST-BODY.  If this fails,
1087# try again with each compiler option in the space-separated OPTION-LIST; if one
1088# helps, append it to CC.  If eventually successful, run ACTION-IF-AVAILABLE,
1089# else ACTION-IF-UNAVAILABLE.
1090AC_DEFUN([_AC_C_STD_TRY],
1091[AC_MSG_CHECKING([for $CC option to accept ISO ]m4_translit($1, [c], [C]))
1092AC_CACHE_VAL(ac_cv_prog_cc_$1,
1093[ac_cv_prog_cc_$1=no
1094ac_save_CC=$CC
1095AC_LANG_CONFTEST([AC_LANG_PROGRAM([$2], [$3])])
1096for ac_arg in '' $4
1097do
1098  CC="$ac_save_CC $ac_arg"
1099  _AC_COMPILE_IFELSE([], [ac_cv_prog_cc_$1=$ac_arg])
1100  test "x$ac_cv_prog_cc_$1" != "xno" && break
1101done
1102rm -f conftest.$ac_ext
1103CC=$ac_save_CC
1104])# AC_CACHE_VAL
1105case "x$ac_cv_prog_cc_$1" in
1106  x)
1107    AC_MSG_RESULT([none needed]) ;;
1108  xno)
1109    AC_MSG_RESULT([unsupported]) ;;
1110  *)
1111    CC="$CC $ac_cv_prog_cc_$1"
1112    AC_MSG_RESULT([$ac_cv_prog_cc_$1]) ;;
1113esac
1114AS_IF([test "x$ac_cv_prog_cc_$1" != xno], [$5], [$6])
1115])# _AC_C_STD_TRY
1116
1117
1118# _AC_PROG_CC_C99 ([ACTION-IF-AVAILABLE], [ACTION-IF-UNAVAILABLE])
1119# ----------------------------------------------------------------
1120# If the C compiler is not in ISO C99 mode by default, try to add an
1121# option to output variable CC to make it so.  This macro tries
1122# various options that select ISO C99 on some system or another.  It
1123# considers the compiler to be in ISO C99 mode if it handles _Bool,
1124# // comments, flexible array members, inline, long long int, mixed
1125# code and declarations, named initialization of structs, restrict,
1126# va_copy, varargs macros, variable declarations in for loops and
1127# variable length arrays.
1128AC_DEFUN([_AC_PROG_CC_C99],
1129[_AC_C_STD_TRY([c99],
1130[[#include <stdarg.h>
1131#include <stdbool.h>
1132#include <stdlib.h>
1133#include <wchar.h>
1134#include <stdio.h>
1135
1136// Check varargs macros.  These examples are taken from C99 6.10.3.5.
1137#define debug(...) fprintf (stderr, __VA_ARGS__)
1138#define showlist(...) puts (#__VA_ARGS__)
1139#define report(test,...) ((test) ? puts (#test) : printf (__VA_ARGS__))
1140static void
1141test_varargs_macros (void)
1142{
1143  int x = 1234;
1144  int y = 5678;
1145  debug ("Flag");
1146  debug ("X = %d\n", x);
1147  showlist (The first, second, and third items.);
1148  report (x>y, "x is %d but y is %d", x, y);
1149}
1150
1151// Check long long types.
1152#define BIG64 18446744073709551615ull
1153#define BIG32 4294967295ul
1154#define BIG_OK (BIG64 / BIG32 == 4294967297ull && BIG64 % BIG32 == 0)
1155#if !BIG_OK
1156  your preprocessor is broken;
1157#endif
1158#if BIG_OK
1159#else
1160  your preprocessor is broken;
1161#endif
1162static long long int bignum = -9223372036854775807LL;
1163static unsigned long long int ubignum = BIG64;
1164
1165struct incomplete_array
1166{
1167  int datasize;
1168  double data[];
1169};
1170
1171struct named_init {
1172  int number;
1173  const wchar_t *name;
1174  double average;
1175};
1176
1177typedef const char *ccp;
1178
1179static inline int
1180test_restrict (ccp restrict text)
1181{
1182  // See if C++-style comments work.
1183  // Iterate through items via the restricted pointer.
1184  // Also check for declarations in for loops.
1185  for (unsigned int i = 0; *(text+i) != '\0'; ++i)
1186    continue;
1187  return 0;
1188}
1189
1190// Check varargs and va_copy.
1191static void
1192test_varargs (const char *format, ...)
1193{
1194  va_list args;
1195  va_start (args, format);
1196  va_list args_copy;
1197  va_copy (args_copy, args);
1198
1199  const char *str;
1200  int number;
1201  float fnumber;
1202
1203  while (*format)
1204    {
1205      switch (*format++)
1206	{
1207	case 's': // string
1208	  str = va_arg (args_copy, const char *);
1209	  break;
1210	case 'd': // int
1211	  number = va_arg (args_copy, int);
1212	  break;
1213	case 'f': // float
1214	  fnumber = va_arg (args_copy, double);
1215	  break;
1216	default:
1217	  break;
1218	}
1219    }
1220  va_end (args_copy);
1221  va_end (args);
1222}
1223]],
1224[[
1225  // Check bool.
1226  _Bool success = false;
1227
1228  // Check restrict.
1229  if (test_restrict ("String literal") == 0)
1230    success = true;
1231  char *restrict newvar = "Another string";
1232
1233  // Check varargs.
1234  test_varargs ("s, d' f .", "string", 65, 34.234);
1235  test_varargs_macros ();
1236
1237  // Check flexible array members.
1238  struct incomplete_array *ia =
1239    malloc (sizeof (struct incomplete_array) + (sizeof (double) * 10));
1240  ia->datasize = 10;
1241  for (int i = 0; i < ia->datasize; ++i)
1242    ia->data[i] = i * 1.234;
1243
1244  // Check named initializers.
1245  struct named_init ni = {
1246    .number = 34,
1247    .name = L"Test wide string",
1248    .average = 543.34343,
1249  };
1250
1251  ni.number = 58;
1252
1253  int dynamic_array[ni.number];
1254  dynamic_array[ni.number - 1] = 543;
1255
1256  // work around unused variable warnings
1257  return (!success || bignum == 0LL || ubignum == 0uLL || newvar[0] == 'x'
1258	  || dynamic_array[ni.number - 1] != 543);
1259]],
1260dnl Try
1261dnl GCC		-std=gnu99 (unused restrictive modes: -std=c99 -std=iso9899:1999)
1262dnl AIX		-qlanglvl=extc99 (unused restrictive mode: -qlanglvl=stdc99)
1263dnl Intel ICC	-c99
1264dnl IRIX	-c99
1265dnl Solaris	(unused because it causes the compiler to assume C99 semantics for
1266dnl		library functions, and this is invalid before Solaris 10: -xc99)
1267dnl Tru64	-c99
1268dnl with extended modes being tried first.
1269[[-std=gnu99 -c99 -qlanglvl=extc99]], [$1], [$2])[]dnl
1270])# _AC_PROG_CC_C99
1271
1272
1273# AC_PROG_CC_C89
1274# --------------
1275AC_DEFUN([AC_PROG_CC_C89],
1276[ AC_REQUIRE([AC_PROG_CC])dnl
1277  _AC_PROG_CC_C89
1278])
1279
1280
1281# AC_PROG_CC_C99
1282# --------------
1283AC_DEFUN([AC_PROG_CC_C99],
1284[ AC_REQUIRE([AC_PROG_CC])dnl
1285  _AC_PROG_CC_C99
1286])
1287
1288
1289# AC_PROG_CC_STDC
1290# ---------------
1291AC_DEFUN([AC_PROG_CC_STDC],
1292[ AC_REQUIRE([AC_PROG_CC])dnl
1293  AS_CASE([$ac_cv_prog_cc_stdc],
1294    [no], [ac_cv_prog_cc_c99=no; ac_cv_prog_cc_c89=no],
1295	  [_AC_PROG_CC_C99([ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c99],
1296	     [_AC_PROG_CC_C89([ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c89],
1297			      [ac_cv_prog_cc_stdc=no])])])dnl
1298  AC_MSG_CHECKING([for $CC option to accept ISO Standard C])
1299  AC_CACHE_VAL([ac_cv_prog_cc_stdc], [])
1300  AS_CASE([$ac_cv_prog_cc_stdc],
1301    [no], [AC_MSG_RESULT([unsupported])],
1302    [''], [AC_MSG_RESULT([none needed])],
1303          [AC_MSG_RESULT([$ac_cv_prog_cc_stdc])])
1304])
1305
1306
1307# AC_C_BACKSLASH_A
1308# ----------------
1309AC_DEFUN([AC_C_BACKSLASH_A],
1310[
1311  AC_CACHE_CHECK([whether backslash-a works in strings], ac_cv_c_backslash_a,
1312   [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],
1313     [[
1314#if '\a' == 'a'
1315      syntax error;
1316#endif
1317      char buf['\a' == 'a' ? -1 : 1];
1318      buf[0] = '\a';
1319      return buf[0] != "\a"[0];
1320     ]])],
1321     [ac_cv_c_backslash_a=yes],
1322     [ac_cv_c_backslash_a=no])])
1323  if test $ac_cv_c_backslash_a = yes; then
1324    AC_DEFINE(HAVE_C_BACKSLASH_A, 1,
1325      [Define if backslash-a works in C strings.])
1326  fi
1327])
1328
1329
1330# AC_C_CROSS
1331# ----------
1332# Has been merged into AC_PROG_CC.
1333AU_DEFUN([AC_C_CROSS], [])
1334
1335
1336# AC_C_CHAR_UNSIGNED
1337# ------------------
1338AC_DEFUN([AC_C_CHAR_UNSIGNED],
1339[AH_VERBATIM([__CHAR_UNSIGNED__],
1340[/* Define to 1 if type `char' is unsigned and you are not using gcc.  */
1341#ifndef __CHAR_UNSIGNED__
1342# undef __CHAR_UNSIGNED__
1343#endif])dnl
1344AC_CACHE_CHECK(whether char is unsigned, ac_cv_c_char_unsigned,
1345[AC_COMPILE_IFELSE([AC_LANG_BOOL_COMPILE_TRY([AC_INCLUDES_DEFAULT([])],
1346					     [((char) -1) < 0])],
1347		   ac_cv_c_char_unsigned=no, ac_cv_c_char_unsigned=yes)])
1348if test $ac_cv_c_char_unsigned = yes && test "$GCC" != yes; then
1349  AC_DEFINE(__CHAR_UNSIGNED__)
1350fi
1351])# AC_C_CHAR_UNSIGNED
1352
1353
1354# AC_C_BIGENDIAN ([ACTION-IF-TRUE], [ACTION-IF-FALSE], [ACTION-IF-UNKNOWN])
1355# -------------------------------------------------------------------------
1356AC_DEFUN([AC_C_BIGENDIAN],
1357[AC_CACHE_CHECK(whether byte ordering is bigendian, ac_cv_c_bigendian,
1358[# See if sys/param.h defines the BYTE_ORDER macro.
1359AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <sys/types.h>
1360#include <sys/param.h>
1361],
1362[#if  ! (defined BYTE_ORDER && defined BIG_ENDIAN && defined LITTLE_ENDIAN \
1363	&& BYTE_ORDER && BIG_ENDIAN && LITTLE_ENDIAN)
1364 bogus endian macros
1365#endif
1366])],
1367[# It does; now see whether it defined to BIG_ENDIAN or not.
1368AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <sys/types.h>
1369#include <sys/param.h>
1370], [#if BYTE_ORDER != BIG_ENDIAN
1371 not big endian
1372#endif
1373])], [ac_cv_c_bigendian=yes], [ac_cv_c_bigendian=no])],
1374[# It does not; compile a test program.
1375AC_RUN_IFELSE(
1376[AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT], [[
1377  /* Are we little or big endian?  From Harbison&Steele.  */
1378  union
1379  {
1380    long int l;
1381    char c[sizeof (long int)];
1382  } u;
1383  u.l = 1;
1384  return u.c[sizeof (long int) - 1] == 1;
1385]])],
1386	      [ac_cv_c_bigendian=no],
1387	      [ac_cv_c_bigendian=yes],
1388[# try to guess the endianness by grepping values into an object file
1389  ac_cv_c_bigendian=unknown
1390  AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
1391[[short int ascii_mm[] = { 0x4249, 0x4765, 0x6E44, 0x6961, 0x6E53, 0x7953, 0 };
1392short int ascii_ii[] = { 0x694C, 0x5454, 0x656C, 0x6E45, 0x6944, 0x6E61, 0 };
1393void _ascii () { char *s = (char *) ascii_mm; s = (char *) ascii_ii; }
1394short int ebcdic_ii[] = { 0x89D3, 0xE3E3, 0x8593, 0x95C5, 0x89C4, 0x9581, 0 };
1395short int ebcdic_mm[] = { 0xC2C9, 0xC785, 0x95C4, 0x8981, 0x95E2, 0xA8E2, 0 };
1396void _ebcdic () { char *s = (char *) ebcdic_mm; s = (char *) ebcdic_ii; }]],
1397[[ _ascii (); _ebcdic (); ]])],
1398[if grep BIGenDianSyS conftest.$ac_objext >/dev/null ; then
1399  ac_cv_c_bigendian=yes
1400fi
1401if grep LiTTleEnDian conftest.$ac_objext >/dev/null ; then
1402  if test "$ac_cv_c_bigendian" = unknown; then
1403    ac_cv_c_bigendian=no
1404  else
1405    # finding both strings is unlikely to happen, but who knows?
1406    ac_cv_c_bigendian=unknown
1407  fi
1408fi])])])])
1409case $ac_cv_c_bigendian in
1410  yes)
1411    m4_default([$1],
1412      [AC_DEFINE([WORDS_BIGENDIAN], 1,
1413	[Define to 1 if your processor stores words with the most significant
1414	 byte first (like Motorola and SPARC, unlike Intel and VAX).])]) ;;
1415  no)
1416    $2 ;;
1417  *)
1418    m4_default([$3],
1419      [AC_MSG_ERROR([unknown endianness
1420presetting ac_cv_c_bigendian=no (or yes) will help])]) ;;
1421esac
1422])# AC_C_BIGENDIAN
1423
1424
1425# AC_C_INLINE
1426# -----------
1427# Do nothing if the compiler accepts the inline keyword.
1428# Otherwise define inline to __inline__ or __inline if one of those work,
1429# otherwise define inline to be empty.
1430#
1431# HP C version B.11.11.04 doesn't allow a typedef as the return value for an
1432# inline function, only builtin types.
1433#
1434AN_IDENTIFIER([inline], [AC_C_INLINE])
1435AC_DEFUN([AC_C_INLINE],
1436[AC_CACHE_CHECK([for inline], ac_cv_c_inline,
1437[ac_cv_c_inline=no
1438for ac_kw in inline __inline__ __inline; do
1439  AC_COMPILE_IFELSE([AC_LANG_SOURCE(
1440[#ifndef __cplusplus
1441typedef int foo_t;
1442static $ac_kw foo_t static_foo () {return 0; }
1443$ac_kw foo_t foo () {return 0; }
1444#endif
1445])],
1446		    [ac_cv_c_inline=$ac_kw])
1447  test "$ac_cv_c_inline" != no && break
1448done
1449])
1450AH_VERBATIM([inline],
1451[/* Define to `__inline__' or `__inline' if that's what the C compiler
1452   calls it, or to nothing if 'inline' is not supported under any name.  */
1453#ifndef __cplusplus
1454#undef inline
1455#endif])
1456case $ac_cv_c_inline in
1457  inline | yes) ;;
1458  *)
1459    case $ac_cv_c_inline in
1460      no) ac_val=;;
1461      *) ac_val=$ac_cv_c_inline;;
1462    esac
1463    cat >>confdefs.h <<_ACEOF
1464#ifndef __cplusplus
1465#define inline $ac_val
1466#endif
1467_ACEOF
1468    ;;
1469esac
1470])# AC_C_INLINE
1471
1472
1473# AC_C_CONST
1474# ----------
1475AN_IDENTIFIER([const],  [AC_C_CONST])
1476AC_DEFUN([AC_C_CONST],
1477[AC_CACHE_CHECK([for an ANSI C-conforming const], ac_cv_c_const,
1478[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],
1479[[/* FIXME: Include the comments suggested by Paul. */
1480#ifndef __cplusplus
1481  /* Ultrix mips cc rejects this.  */
1482  typedef int charset[2];
1483  const charset cs;
1484  /* SunOS 4.1.1 cc rejects this.  */
1485  char const *const *pcpcc;
1486  char **ppc;
1487  /* NEC SVR4.0.2 mips cc rejects this.  */
1488  struct point {int x, y;};
1489  static struct point const zero = {0,0};
1490  /* AIX XL C 1.02.0.0 rejects this.
1491     It does not let you subtract one const X* pointer from another in
1492     an arm of an if-expression whose if-part is not a constant
1493     expression */
1494  const char *g = "string";
1495  pcpcc = &g + (g ? g-g : 0);
1496  /* HPUX 7.0 cc rejects these. */
1497  ++pcpcc;
1498  ppc = (char**) pcpcc;
1499  pcpcc = (char const *const *) ppc;
1500  { /* SCO 3.2v4 cc rejects this.  */
1501    char *t;
1502    char const *s = 0 ? (char *) 0 : (char const *) 0;
1503
1504    *t++ = 0;
1505    if (s) return 0;
1506  }
1507  { /* Someone thinks the Sun supposedly-ANSI compiler will reject this.  */
1508    int x[] = {25, 17};
1509    const int *foo = &x[0];
1510    ++foo;
1511  }
1512  { /* Sun SC1.0 ANSI compiler rejects this -- but not the above. */
1513    typedef const int *iptr;
1514    iptr p = 0;
1515    ++p;
1516  }
1517  { /* AIX XL C 1.02.0.0 rejects this saying
1518       "k.c", line 2.27: 1506-025 (S) Operand must be a modifiable lvalue. */
1519    struct s { int j; const int *ap[3]; };
1520    struct s *b; b->j = 5;
1521  }
1522  { /* ULTRIX-32 V3.1 (Rev 9) vcc rejects this */
1523    const int foo = 10;
1524    if (!foo) return 0;
1525  }
1526  return !cs[0] && !zero.x;
1527#endif
1528]])],
1529		   [ac_cv_c_const=yes],
1530		   [ac_cv_c_const=no])])
1531if test $ac_cv_c_const = no; then
1532  AC_DEFINE(const,,
1533	    [Define to empty if `const' does not conform to ANSI C.])
1534fi
1535])# AC_C_CONST
1536
1537
1538# AC_C_RESTRICT
1539# -------------
1540# based on acx_restrict.m4, from the GNU Autoconf Macro Archive at:
1541# http://autoconf-archive.cryp.to/acx_restrict.html
1542#
1543# Determine whether the C/C++ compiler supports the "restrict" keyword
1544# introduced in ANSI C99, or an equivalent.  Do nothing if the compiler
1545# accepts it.  Otherwise, if the compiler supports an equivalent,
1546# define "restrict" to be that.  Here are some variants:
1547# - GCC supports both __restrict and __restrict__
1548# - older DEC Alpha C compilers support only __restrict
1549# - _Restrict is the only spelling accepted by Sun WorkShop 6 update 2 C
1550# Otherwise, define "restrict" to be empty.
1551AN_IDENTIFIER([restrict], [AC_C_RESTRICT])
1552AC_DEFUN([AC_C_RESTRICT],
1553[AC_CACHE_CHECK([for C/C++ restrict keyword], ac_cv_c_restrict,
1554  [ac_cv_c_restrict=no
1555   # Try the official restrict keyword, then gcc's __restrict, and
1556   # the less common variants.
1557   for ac_kw in restrict __restrict __restrict__ _Restrict; do
1558     AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
1559      [[typedef int * int_ptr;
1560        int foo (int_ptr $ac_kw ip) {
1561        return ip[0];
1562       }]],
1563      [[int s[1];
1564        int * $ac_kw t = s;
1565        t[0] = 0;
1566        return foo(t)]])],
1567      [ac_cv_c_restrict=$ac_kw])
1568     test "$ac_cv_c_restrict" != no && break
1569   done
1570  ])
1571 case $ac_cv_c_restrict in
1572   restrict) ;;
1573   no) AC_DEFINE(restrict,,
1574	[Define to equivalent of C99 restrict keyword, or to nothing if this
1575	is not supported.  Do not define if restrict is supported directly.]) ;;
1576   *)  AC_DEFINE_UNQUOTED(restrict, $ac_cv_c_restrict) ;;
1577 esac
1578])# AC_C_RESTRICT
1579
1580
1581# AC_C_VOLATILE
1582# -------------
1583# Note that, unlike const, #defining volatile to be the empty string can
1584# actually turn a correct program into an incorrect one, since removing
1585# uses of volatile actually grants the compiler permission to perform
1586# optimizations that could break the user's code.  So, do not #define
1587# volatile away unless it is really necessary to allow the user's code
1588# to compile cleanly.  Benign compiler failures should be tolerated.
1589AN_IDENTIFIER([volatile], [AC_C_VOLATILE])
1590AC_DEFUN([AC_C_VOLATILE],
1591[AC_CACHE_CHECK([for working volatile], ac_cv_c_volatile,
1592[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [
1593volatile int x;
1594int * volatile y = (int *) 0;
1595return !x && !y;])],
1596		   [ac_cv_c_volatile=yes],
1597		   [ac_cv_c_volatile=no])])
1598if test $ac_cv_c_volatile = no; then
1599  AC_DEFINE(volatile,,
1600	    [Define to empty if the keyword `volatile' does not work.
1601	     Warning: valid code using `volatile' can become incorrect
1602	     without.  Disable with care.])
1603fi
1604])# AC_C_VOLATILE
1605
1606
1607# AC_C_STRINGIZE
1608# --------------
1609# Checks if `#' can be used to glue strings together at the CPP level.
1610# Defines HAVE_STRINGIZE if positive.
1611AC_DEFUN([AC_C_STRINGIZE],
1612[AC_CACHE_CHECK([for preprocessor stringizing operator],
1613		[ac_cv_c_stringize],
1614[AC_EGREP_CPP([@%:@teststring],
1615	      [@%:@define x(y) #y
1616
1617char *s = x(teststring);],
1618	      [ac_cv_c_stringize=no],
1619	      [ac_cv_c_stringize=yes])])
1620if test $ac_cv_c_stringize = yes; then
1621  AC_DEFINE(HAVE_STRINGIZE, 1,
1622	    [Define to 1 if cpp supports the ANSI @%:@ stringizing operator.])
1623fi
1624])# AC_C_STRINGIZE
1625
1626
1627# AC_C_PROTOTYPES
1628# ---------------
1629# Check if the C compiler supports prototypes, included if it needs
1630# options.
1631AC_DEFUN([AC_C_PROTOTYPES],
1632[AC_REQUIRE([AC_PROG_CC])dnl
1633AC_MSG_CHECKING([for function prototypes])
1634if test "$ac_cv_prog_cc_c89" != no; then
1635  AC_MSG_RESULT([yes])
1636  AC_DEFINE(PROTOTYPES, 1,
1637	    [Define to 1 if the C compiler supports function prototypes.])
1638  AC_DEFINE(__PROTOTYPES, 1,
1639	    [Define like PROTOTYPES; this can be used by system headers.])
1640else
1641  AC_MSG_RESULT([no])
1642fi
1643])# AC_C_PROTOTYPES
1644
1645
1646# AC_C_FLEXIBLE_ARRAY_MEMBER
1647# --------------------------
1648# Check whether the C compiler supports flexible array members.
1649AC_DEFUN([AC_C_FLEXIBLE_ARRAY_MEMBER],
1650[
1651  AC_CACHE_CHECK([for flexible array members],
1652    ac_cv_c_flexmember,
1653    [AC_COMPILE_IFELSE(
1654       [AC_LANG_PROGRAM(
1655	  [[#include <stdlib.h>
1656	    #include <stdio.h>
1657	    #include <stddef.h>
1658	    struct s { int n; double d[]; };]],
1659	  [[int m = getchar ();
1660	    struct s *p = malloc (offsetof (struct s, d)
1661				  + m * sizeof (double));
1662	    p->d[0] = 0.0;
1663	    return p->d != (double *) NULL;]])],
1664       [ac_cv_c_flexmember=yes],
1665       [ac_cv_c_flexmember=no])])
1666  if test $ac_cv_c_flexmember = yes; then
1667    AC_DEFINE([FLEXIBLE_ARRAY_MEMBER], [],
1668      [Define to nothing if C supports flexible array members, and to
1669       1 if it does not.  That way, with a declaration like `struct s
1670       { int n; double d@<:@FLEXIBLE_ARRAY_MEMBER@:>@; };', the struct hack
1671       can be used with pre-C99 compilers.
1672       When computing the size of such an object, don't use 'sizeof (struct s)'
1673       as it overestimates the size.  Use 'offsetof (struct s, d)' instead.
1674       Don't use 'offsetof (struct s, d@<:@0@:>@)', as this doesn't work with
1675       MSVC and with C++ compilers.])
1676  else
1677    AC_DEFINE([FLEXIBLE_ARRAY_MEMBER], 1)
1678  fi
1679])
1680
1681
1682# AC_C_VARARRAYS
1683# --------------
1684# Check whether the C compiler supports variable-length arrays.
1685AC_DEFUN([AC_C_VARARRAYS],
1686[
1687  AC_CACHE_CHECK([for variable-length arrays],
1688    ac_cv_c_vararrays,
1689    [AC_COMPILE_IFELSE(
1690       [AC_LANG_PROGRAM([],
1691	  [[static int x; char a[++x]; a[sizeof a - 1] = 0; return a[0];]])],
1692       [ac_cv_c_vararrays=yes],
1693       [ac_cv_c_vararrays=no])])
1694  if test $ac_cv_c_vararrays = yes; then
1695    AC_DEFINE([HAVE_C_VARARRAYS], 1,
1696      [Define to 1 if C supports variable-length arrays.])
1697  fi
1698])
1699
1700
1701# AC_C_TYPEOF
1702# -----------
1703# Check if the C compiler supports GCC's typeof syntax.
1704# The test case provokes incompatibilities in the Sun C compilers
1705# (both Solaris 8 and Solaris 10).
1706AC_DEFUN([AC_C_TYPEOF],
1707[
1708  AC_CACHE_CHECK([for typeof syntax and keyword spelling], ac_cv_c_typeof,
1709    [ac_cv_c_typeof=no
1710     for ac_kw in typeof __typeof__ no; do
1711       test $ac_kw = no && break
1712       AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],
1713	 [[
1714	   int value;
1715	   typedef struct {
1716		   char a [1
1717			   + ! (($ac_kw (value))
1718				(($ac_kw (value)) 0 < ($ac_kw (value)) -1
1719				 ? ($ac_kw (value)) - 1
1720				 : ~ (~ ($ac_kw (value)) 0
1721				      << sizeof ($ac_kw (value)))))]; }
1722	      ac__typeof_type_;
1723	   return
1724	     (! ((void) ((ac__typeof_type_ *) 0), 0));
1725	 ]])],
1726	 [ac_cv_c_typeof=$ac_kw])
1727       test $ac_cv_c_typeof != no && break
1728     done])
1729  if test $ac_cv_c_typeof != no; then
1730    AC_DEFINE([HAVE_TYPEOF], 1,
1731      [Define to 1 if typeof works with your compiler.])
1732    if test $ac_cv_c_typeof != typeof; then
1733      AC_DEFINE_UNQUOTED([typeof], [$ac_cv_c_typeof],
1734	[Define to __typeof__ if your compiler spells it that way.])
1735    fi
1736  fi
1737])
1738