1 dnl ---------------------------------------------------------------------------
3 dnl Macros for configure.in for wxWindows by Robert Roebling, Phil Blecker,
4 dnl Vadim Zeitlin and Ron Lee
6 dnl This script is under the wxWindows licence.
9 dnl ---------------------------------------------------------------------------
12 dnl ===========================================================================
13 dnl Objective-C(++) related macros
14 dnl ===========================================================================
15 m4_define([AC_WX_LANG_OBJECTIVEC],
20 m4_define([AC_WX_LANG_OBJECTIVECPLUSPLUS],
25 dnl ===========================================================================
26 dnl macros to find the a file in the list of include/lib paths
27 dnl ===========================================================================
29 dnl ---------------------------------------------------------------------------
30 dnl call WX_PATH_FIND_INCLUDES(search path, header name), sets ac_find_includes
31 dnl to the full name of the file that was found or leaves it empty if not found
32 dnl ---------------------------------------------------------------------------
33 AC_DEFUN([WX_PATH_FIND_INCLUDES],
36 for ac_dir in $1 /usr/include;
38 if test -f "$ac_dir/$2"; then
39 ac_find_includes=$ac_dir
45 dnl ---------------------------------------------------------------------------
46 dnl call WX_PATH_FIND_LIBRARIES(search path, lib name), sets ac_find_libraries
47 dnl to the full name of the file that was found or leaves it empty if not found
48 dnl ---------------------------------------------------------------------------
49 AC_DEFUN([WX_PATH_FIND_LIBRARIES],
54 for ac_extension in a so sl dylib dll.a; do
55 if test -f "$ac_dir/lib$2.$ac_extension"; then
56 ac_find_libraries=$ac_dir
63 dnl ---------------------------------------------------------------------------
64 dnl return list of standard library paths
65 dnl ---------------------------------------------------------------------------
66 dnl return all default locations:
67 dnl - /usr/lib: standard
68 dnl - /usr/lib32: n32 ABI on IRIX
69 dnl - /usr/lib64: n64 ABI on IRIX
70 dnl - /usr/lib/64: 64 bit ABI on Solaris and Linux x86-64
72 dnl NB: if any of directories in the list is not a subdir of /usr, code setting
73 dnl wx_cv_std_libpath needs to be updated
74 AC_DEFUN([WX_STD_LIBPATH], [/usr/lib /usr/lib32 /usr/lib/64 /usr/lib64])
76 dnl ---------------------------------------------------------------------------
77 dnl Path to include, already defined
78 dnl ---------------------------------------------------------------------------
79 AC_DEFUN([WX_INCLUDE_PATH_EXIST],
81 dnl never add -I/usr/include to the CPPFLAGS
82 if test "x$1" = "x/usr/include"; then
85 echo "$2" | grep "\-I$1" > /dev/null
87 if test $result = 0; then
90 ac_path_to_include=" -I$1"
95 dnl ---------------------------------------------------------------------------
96 dnl Usage: WX_LINK_PATH_EXIST(path, libpath)
98 dnl Set ac_path_to_link to nothing if path is already in libpath of to -Lpath
99 dnl if it is not, so that libpath can be set to "$libpath$ac_path_to_link"
100 dnl after calling this function
101 dnl ---------------------------------------------------------------------------
102 AC_DEFUN([WX_LINK_PATH_EXIST],
104 dnl never add -L/usr/libXXX explicitely to libpath
105 if test "$1" = "default location"; then
108 echo "$2" | grep "\-L$1" > /dev/null
110 if test $result = 0; then
113 ac_path_to_link=" -L$1"
118 dnl ===========================================================================
119 dnl C++ features test
120 dnl ===========================================================================
122 dnl ---------------------------------------------------------------------------
123 dnl WX_CPP_NEW_HEADERS checks whether the compiler has "new" <iostream> header
124 dnl or only the old <iostream.h> one - it may be generally assumed that if
125 dnl <iostream> exists, the other "new" headers (without .h) exist too.
127 dnl call WX_CPP_NEW_HEADERS(actiof-if-true, action-if-false)
128 dnl ---------------------------------------------------------------------------
130 AC_DEFUN([WX_CPP_NEW_HEADERS],
135 AC_CHECK_HEADER(iostream,,, [ ])
137 if test "$ac_cv_header_iostream" = "yes" ; then
138 ifelse([$1], , :, [$1])
140 ifelse([$2], , :, [$2])
146 dnl ---------------------------------------------------------------------------
147 dnl WX_CPP_BOOL checks whether the C++ compiler has a built in bool type
149 dnl call WX_CPP_BOOL - will define HAVE_BOOL if the compiler supports bool
150 dnl ---------------------------------------------------------------------------
152 AC_DEFUN([WX_CPP_BOOL],
154 AC_CACHE_CHECK([if C++ compiler supports bool], wx_cv_cpp_bool,
178 if test "$wx_cv_cpp_bool" = "yes"; then
183 dnl ---------------------------------------------------------------------------
184 dnl WX_CPP_EXPLICIT checks whether the C++ compiler support the explicit
185 dnl keyword and defines HAVE_EXPLICIT if this is the case
186 dnl ---------------------------------------------------------------------------
188 AC_DEFUN([WX_CPP_EXPLICIT],
190 AC_CACHE_CHECK([if C++ compiler supports the explicit keyword],
196 dnl do the test in 2 steps: first check that the compiler knows about the
197 dnl explicit keyword at all and then verify that it really honours it
200 class Foo { public: explicit Foo(int) {} };
208 class Foo { public: explicit Foo(int) {} };
209 static void TakeFoo(const Foo& foo) { }
225 if test "$wx_cv_explicit" = "yes"; then
226 AC_DEFINE(HAVE_EXPLICIT)
230 dnl ---------------------------------------------------------------------------
231 dnl WX_CHECK_FUNCS(FUNCTIONS...,
232 dnl [ACTION-IF-FOUND],
233 dnl [ACTION-IF-NOT-FOUND],
234 dnl [EXTRA-DEFINES-AND-INCLUDES],
235 dnl [EXTRA-TEST-CODE])
237 dnl Checks that the functions listed in FUNCTIONS exist in the headers and the
238 dnl libs. For each function, if it is found then defines 'HAVE_FUNCTION' and
239 dnl executes ACTION-IF-FOUND, otherwise executes ACTION-IF-NOT-FOUND.
241 dnl The code from EXTRA-DEFINES-AND-INCLUDES is inserted into the test before
242 dnl the default headers are included, and EXTRA-TEST-CODE is inserted into
243 dnl the main() function after the default test for existence.
246 dnl # the simple case
247 dnl WX_CHECK_FUNCS(stat)
248 dnl # use break to finish the loop early
249 dnl WX_CHECK_FUNCS(mkstemp mktemp, break)
251 dnl WX_CHECK_FUNCS(strtok_r, [], [], [#define _RREENTRANT])
253 dnl WX_CHECK_FUNCS(swprintf, [], [], [#include <wchar.h>])
254 dnl # checking the signature with extra test code
255 dnl WX_CHECK_FUNCS(gettimeofday, [], [], [#include <sys/time.h>]
256 dnl [struct timeval tv; struct timezone tz; gettimeofday(&tv, &tz)])
257 dnl ---------------------------------------------------------------------------
259 AC_DEFUN([WX_CHECK_FUNCS],
265 [wx_cv_func_$wx_func],
281 [eval wx_cv_func_$wx_func=yes],
282 [eval wx_cv_func_$wx_func=no])
285 if eval test \$wx_cv_func_$wx_func = yes
287 AC_DEFINE_UNQUOTED([HAVE_`echo $wx_func | tr 'a-z' 'A-Z'`])
296 dnl ---------------------------------------------------------------------------
297 dnl a slightly better AC_C_BIGENDIAN macro which allows cross-compiling
298 dnl ---------------------------------------------------------------------------
300 AC_DEFUN([WX_C_BIGENDIAN],
301 [AC_CACHE_CHECK([whether byte ordering is bigendian], ac_cv_c_bigendian,
302 [ac_cv_c_bigendian=unknown
303 # See if sys/param.h defines the BYTE_ORDER macro.
304 AC_TRY_COMPILE([#include <sys/types.h>
305 #include <sys/param.h>], [
306 #if !BYTE_ORDER || !BIG_ENDIAN || !LITTLE_ENDIAN
308 #endif], [# It does; now see whether it defined to BIG_ENDIAN or not.
309 AC_TRY_COMPILE([#include <sys/types.h>
310 #include <sys/param.h>], [
311 #if BYTE_ORDER != BIG_ENDIAN
313 #endif], ac_cv_c_bigendian=yes, ac_cv_c_bigendian=no)])
314 if test $ac_cv_c_bigendian = unknown; then
315 AC_TRY_RUN([main () {
316 /* Are we little or big endian? From Harbison&Steele. */
320 char c[sizeof (long)];
323 exit (u.c[sizeof (long) - 1] == 1);
324 }], [ac_cv_c_bigendian=no], [ac_cv_c_bigendian=yes], [ac_cv_c_bigendian=unknown])
326 if test $ac_cv_c_bigendian = unknown; then
327 AC_MSG_WARN([Assuming little-endian target machine - this may be overriden by adding the line "ac_cv_c_bigendian=${ac_cv_c_bigendian='yes'}" to config.cache file])
329 if test $ac_cv_c_bigendian = yes; then
330 AC_DEFINE(WORDS_BIGENDIAN)
334 dnl ---------------------------------------------------------------------------
335 dnl override AC_ARG_ENABLE/WITH to cache the results in .cache file
336 dnl ---------------------------------------------------------------------------
338 AC_DEFUN([WX_ARG_CACHE_INIT],
340 wx_arg_cache_file="configarg.cache"
341 echo "loading argument cache $wx_arg_cache_file"
342 rm -f ${wx_arg_cache_file}.tmp
343 touch ${wx_arg_cache_file}.tmp
344 touch ${wx_arg_cache_file}
347 AC_DEFUN([WX_ARG_CACHE_FLUSH],
349 echo "saving argument cache $wx_arg_cache_file"
350 mv ${wx_arg_cache_file}.tmp ${wx_arg_cache_file}
353 dnl this macro checks for a three-valued command line --with argument:
354 dnl possible arguments are 'yes', 'no', 'sys', or 'builtin'
355 dnl usage: WX_ARG_SYS_WITH(option, helpmessage, variable-name)
356 AC_DEFUN([WX_ARG_SYS_WITH],
358 AC_MSG_CHECKING([for --with-$1])
360 AC_ARG_WITH($1, [$2],
362 if test "$withval" = yes; then
363 ac_cv_use_$1='$3=yes'
364 elif test "$withval" = no; then
366 elif test "$withval" = sys; then
367 ac_cv_use_$1='$3=sys'
368 elif test "$withval" = builtin; then
369 ac_cv_use_$1='$3=builtin'
371 AC_MSG_ERROR([Invalid value for --with-$1: should be yes, no, sys, or builtin])
375 LINE=`grep "$3" ${wx_arg_cache_file}`
376 if test "x$LINE" != x ; then
382 ac_cv_use_$1='$3='$DEFAULT_$3
386 if test "$no_cache" != 1; then
387 echo $ac_cv_use_$1 >> ${wx_arg_cache_file}.tmp
390 if test "$$3" = yes; then
392 elif test "$$3" = no; then
394 elif test "$$3" = sys; then
395 AC_MSG_RESULT([system version])
396 elif test "$$3" = builtin; then
397 AC_MSG_RESULT([builtin version])
399 AC_MSG_ERROR([Invalid value for --with-$1: should be yes, no, sys, or builtin])
403 dnl this macro checks for a command line argument and caches the result
404 dnl usage: WX_ARG_WITH(option, helpmessage, variable-name, [withstring])
405 AC_DEFUN([WX_ARG_WITH],
408 AC_MSG_CHECKING([for --${withstring:-with}-$1])
410 AC_ARG_WITH($1, [$2],
412 if test "$withval" = yes; then
413 ac_cv_use_$1='$3=yes'
419 LINE=`grep "$3" ${wx_arg_cache_file}`
420 if test "x$LINE" != x ; then
426 ac_cv_use_$1='$3='$DEFAULT_$3
430 if test "$no_cache" != 1; then
431 echo $ac_cv_use_$1 >> ${wx_arg_cache_file}.tmp
434 if test "$$3" = yes; then
441 dnl like WX_ARG_WITH but uses AC_ARG_ENABLE instead of AC_ARG_WITH
442 dnl usage: WX_ARG_ENABLE(option, helpmessage, variable-name, enablestring)
444 dnl enablestring is a hack and allows to show "checking for --disable-foo"
445 dnl message when running configure instead of the default "checking for
446 dnl --enable-foo" one whih is useful for the options enabled by default
447 AC_DEFUN([WX_ARG_ENABLE],
450 AC_MSG_CHECKING([for --${enablestring:-enable}-$1])
452 AC_ARG_ENABLE($1, [$2],
454 if test "$enableval" = yes; then
455 ac_cv_use_$1='$3=yes'
461 LINE=`grep "$3" ${wx_arg_cache_file}`
462 if test "x$LINE" != x ; then
468 ac_cv_use_$1='$3='$DEFAULT_$3
472 if test "$no_cache" != 1; then
473 echo $ac_cv_use_$1 >> ${wx_arg_cache_file}.tmp
476 if test "$$3" = yes; then
484 dnl Like WX_ARG_ENABLE but accepts a parameter.
487 dnl WX_ARG_ENABLE_PARAM(option, helpmessage, variable-name, enablestring)
490 dnl WX_ARG_ENABLE_PARAM(foo, [[ --enable-foo[=bar] use foo]], wxUSE_FOO)
492 dnl --enable-foo wxUSE_FOO=yes
493 dnl --disable-foo wxUSE_FOO=no
494 dnl --enable-foo=bar wxUSE_FOO=bar
495 dnl <not given> value from configarg.cache or wxUSE_FOO=no
497 AC_DEFUN([WX_ARG_ENABLE_PARAM],
500 AC_MSG_CHECKING([for --${enablestring:-enable}-$1])
502 AC_ARG_ENABLE($1, [$2],
504 wx_cv_use_$1="$3='$enableval'"
507 LINE=`grep "$3" ${wx_arg_cache_file}`
508 if test "x$LINE" != x ; then
510 wx_cv_use_$1='$3='$DEFAULT_$3
518 if test "$no_cache" != 1; then
519 echo $wx_cv_use_$1 >> ${wx_arg_cache_file}.tmp
525 dnl ===========================================================================
526 dnl Linker features test
527 dnl ===========================================================================
529 dnl ---------------------------------------------------------------------------
530 dnl WX_VERSIONED_SYMBOLS checks whether the linker can create versioned
531 dnl symbols. If it can, sets LDFLAGS_VERSIONING to $CXX flags needed to use
532 dnl version script file named versionfile
534 dnl call WX_VERSIONED_SYMBOLS(versionfile)
535 dnl ---------------------------------------------------------------------------
536 AC_DEFUN([WX_VERSIONED_SYMBOLS],
539 *-*-cygwin* | *-*-mingw* )
540 dnl although ld does support version script option on these
541 dnl platforms, it doesn't make much sense to use it under Win32
542 dnl and, moreover, this breaks linking because of a bug in handling
543 dnl paths in -Wl,--version-script,path option (if we ever do need
544 dnl to use it for cygwin/mingw32, keep in mind that replacing last
545 dnl comma with the equal sign works) so
546 dnl simply disable it
547 wx_cv_version_script=no
551 AC_CACHE_CHECK([if the linker accepts --version-script], wx_cv_version_script,
553 echo "VER_1 { *; };" >conftest.sym
554 echo "int main() { return 0; }" >conftest.cpp
557 $CXX -o conftest.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp
558 -Wl,--version-script,conftest.sym >/dev/null 2>conftest.stderr]) ; then
559 if test -s conftest.stderr ; then
560 wx_cv_version_script=no
562 wx_cv_version_script=yes
565 wx_cv_version_script=no
568 dnl There's a problem in some old linkers with --version-script that
569 dnl can cause linking to fail when you have objects with vtables in
570 dnl libs 3 deep. This is known to happen in netbsd and openbsd with
573 dnl To test for this we need to make some shared libs and
574 dnl unfortunately we can't be sure of the right way to do that. If the
575 dnl first two compiles don't succeed then it looks like the test isn't
576 dnl working and the result is ignored, but if OTOH the first two
577 dnl succeed but the third does not then the bug has been detected and
578 dnl the --version-script flag is dropped.
579 if test $wx_cv_version_script = yes
581 echo "struct B { virtual ~B() { } }; \
582 struct D : public B { }; \
583 void F() { D d; }" > conftest.cpp
586 $CXX -shared -fPIC -o conftest1.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp
587 -Wl,--version-script,conftest.sym >/dev/null 2>/dev/null]) &&
589 $CXX -shared -fPIC -o conftest2.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp
590 -Wl,--version-script,conftest.sym conftest1.output >/dev/null 2>/dev/null])
593 $CXX -shared -fPIC -o conftest3.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp
594 -Wl,--version-script,conftest.sym conftest2.output conftest1.output >/dev/null 2>/dev/null])
596 wx_cv_version_script=yes
598 wx_cv_version_script=no
603 rm -f conftest.output conftest.stderr conftest.sym conftest.cpp
604 rm -f conftest1.output conftest2.output conftest3.output
607 if test $wx_cv_version_script = yes ; then
608 LDFLAGS_VERSIONING="-Wl,--version-script,$1"
615 dnl ===========================================================================
616 dnl "3rd party" macros included here because they are not widely available
617 dnl ===========================================================================
619 dnl ---------------------------------------------------------------------------
620 dnl test for availability of iconv()
621 dnl ---------------------------------------------------------------------------
623 dnl From Bruno Haible.
627 dnl Some systems have iconv in libc, some have it in libiconv (OSF/1 and
628 dnl those with the standalone portable GNU libiconv installed).
630 AC_ARG_WITH([libiconv-prefix],
631 [ --with-libiconv-prefix=DIR search for libiconv in DIR/include and DIR/lib], [
632 for dir in `echo "$withval" | tr : ' '`; do
633 if test -d $dir/include; then CPPFLAGS="$CPPFLAGS -I$dir/include"; fi
634 if test -d $dir/lib; then LDFLAGS="$LDFLAGS -L$dir/lib"; fi
638 AC_CACHE_CHECK(for iconv, am_cv_func_iconv, [
639 am_cv_func_iconv="no, consider installing GNU libiconv"
641 AC_TRY_LINK([#include <stdlib.h>
643 [iconv_t cd = iconv_open("","");
644 iconv(cd,NULL,NULL,NULL,NULL);
646 am_cv_func_iconv=yes)
647 if test "$am_cv_func_iconv" != yes; then
650 AC_TRY_LINK([#include <stdlib.h>
652 [iconv_t cd = iconv_open("","");
653 iconv(cd,NULL,NULL,NULL,NULL);
656 am_cv_func_iconv=yes)
660 if test "$am_cv_func_iconv" = yes; then
661 AC_DEFINE(HAVE_ICONV, 1, [Define if you have the iconv() function.])
662 AC_CACHE_CHECK([if iconv needs const], wx_cv_func_iconv_const,
670 #if defined(__STDC__) || defined(__cplusplus)
671 size_t iconv (iconv_t cd, char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft);
677 wx_cv_func_iconv_const="no",
678 wx_cv_func_iconv_const="yes"
683 if test "x$wx_cv_func_iconv_const" = "xyes"; then
687 AC_DEFINE_UNQUOTED(ICONV_CONST, $iconv_const,
688 [Define as const if the declaration of iconv() needs const.])
691 if test "$am_cv_lib_iconv" = yes; then
697 dnl ---------------------------------------------------------------------------
698 dnl AC_SYS_LARGEFILE (partly based on the code from autoconf 2.5x)
699 dnl ---------------------------------------------------------------------------
701 dnl WX_SYS_LARGEFILE_TEST
703 dnl NB: original autoconf test was checking if compiler supported 6 bit off_t
704 dnl arithmetic properly but this failed miserably with gcc under Linux
705 dnl whereas the system still supports 64 bit files, so now simply check
706 dnl that off_t is big enough
707 define(WX_SYS_LARGEFILE_TEST,
709 unsigned int field: sizeof(off_t) == 8;
714 dnl WX_SYS_LARGEFILE_MACRO_VALUE(C-MACRO, VALUE, CACHE-VAR)
715 define(WX_SYS_LARGEFILE_MACRO_VALUE,
717 AC_CACHE_CHECK([for $1 value needed for large files], [$3],
719 AC_TRY_COMPILE([#define $1 $2
720 #include <sys/types.h>],
721 WX_SYS_LARGEFILE_TEST,
727 if test "$$3" != no; then
729 AC_DEFINE_UNQUOTED([$1], [$$3])
736 dnl By default, many hosts won't let programs access large files;
737 dnl one must use special compiler options to get large-file access to work.
738 dnl For more details about this brain damage please see:
739 dnl http://www.sas.com/standards/large.file/x_open.20Mar96.html
740 AC_DEFUN([AC_SYS_LARGEFILE],
741 [AC_ARG_ENABLE(largefile,
742 [ --disable-largefile omit support for large files])
743 if test "$enable_largefile" != no; then
744 dnl _FILE_OFFSET_BITS==64 is needed for Linux, Solaris, ...
745 dnl _LARGE_FILES -- for AIX
747 WX_SYS_LARGEFILE_MACRO_VALUE(_FILE_OFFSET_BITS, 64, ac_cv_sys_file_offset_bits)
748 if test "x$wx_largefile" != "xyes"; then
749 WX_SYS_LARGEFILE_MACRO_VALUE(_LARGE_FILES, 1, ac_cv_sys_large_files)
752 AC_MSG_CHECKING(if large file support is available)
753 if test "x$wx_largefile" = "xyes"; then
754 AC_DEFINE(HAVE_LARGEFILE_SUPPORT)
756 AC_MSG_RESULT($wx_largefile)
761 dnl Available from the GNU Autoconf Macro Archive at:
762 dnl http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_const_cast.html
764 AC_DEFUN([AC_CXX_CONST_CAST],
765 [AC_CACHE_CHECK(whether the compiler supports const_cast<>,
766 ac_cv_cxx_const_cast,
769 AC_TRY_COMPILE(,[int x = 0;const int& y = x;int& z = const_cast<int&>(y);return z;],
770 ac_cv_cxx_const_cast=yes, ac_cv_cxx_const_cast=no)
773 if test "$ac_cv_cxx_const_cast" = yes; then
774 AC_DEFINE(HAVE_CONST_CAST,,[define if the compiler supports const_cast<>])
778 dnl http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_reinterpret_cast.html
779 AC_DEFUN([AC_CXX_REINTERPRET_CAST],
780 [AC_CACHE_CHECK(whether the compiler supports reinterpret_cast<>,
781 ac_cv_cxx_reinterpret_cast,
784 AC_TRY_COMPILE([#include <typeinfo>
785 class Base { public : Base () {} virtual void f () = 0;};
786 class Derived : public Base { public : Derived () {} virtual void f () {} };
787 class Unrelated { public : Unrelated () {} };
788 int g (Unrelated&) { return 0; }],[
789 Derived d;Base& b=d;Unrelated& e=reinterpret_cast<Unrelated&>(b);return g(e);],
790 ac_cv_cxx_reinterpret_cast=yes, ac_cv_cxx_reinterpret_cast=no)
793 if test "$ac_cv_cxx_reinterpret_cast" = yes; then
794 AC_DEFINE(HAVE_REINTERPRET_CAST,,
795 [define if the compiler supports reinterpret_cast<>])
799 dnl and http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_static_cast.html
800 AC_DEFUN([AC_CXX_STATIC_CAST],
801 [AC_CACHE_CHECK(whether the compiler supports static_cast<>,
802 ac_cv_cxx_static_cast,
805 AC_TRY_COMPILE([#include <typeinfo>
806 class Base { public : Base () {} virtual void f () = 0; };
807 class Derived : public Base { public : Derived () {} virtual void f () {} };
808 int g (Derived&) { return 0; }],[
809 Derived d; Base& b = d; Derived& s = static_cast<Derived&> (b); return g (s);],
810 ac_cv_cxx_static_cast=yes, ac_cv_cxx_static_cast=no)
813 if test "$ac_cv_cxx_static_cast" = yes; then
814 AC_DEFINE(HAVE_STATIC_CAST,, [define if the compiler supports static_cast<>])
818 dnl http://autoconf-archive.cryp.to/ac_cxx_dynamic_cast.html
819 AC_DEFUN([AC_CXX_DYNAMIC_CAST],
820 [AC_CACHE_CHECK(whether the compiler supports dynamic_cast<>,
821 ac_cv_cxx_dynamic_cast,
824 AC_TRY_COMPILE([#include <typeinfo>
825 class Base { public : Base () {} virtual void f () = 0;};
826 class Derived : public Base { public : Derived () {} virtual void f () {} };],[
827 Derived d; Base& b=d; return dynamic_cast<Derived*>(&b) ? 0 : 1;],
828 ac_cv_cxx_dynamic_cast=yes, ac_cv_cxx_dynamic_cast=no)
831 if test "$ac_cv_cxx_dynamic_cast" = yes; then
832 AC_DEFINE(HAVE_DYNAMIC_CAST,,[define if the compiler supports dynamic_cast<>])