X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/2296fe5018d42d4e0bf9df07c37d31f60d972b32..ffc78010a9d760b6233eec04777d8d036e976204:/acinclude.m4 diff --git a/acinclude.m4 b/acinclude.m4 index 817275d7f4..13973994d3 100644 --- a/acinclude.m4 +++ b/acinclude.m4 @@ -43,9 +43,10 @@ for ac_dir in $1 /usr/include; ]) dnl --------------------------------------------------------------------------- -dnl WX_PATH_FIND_LIBRARIES helper +dnl call WX_PATH_FIND_LIBRARIES(search path, lib name), sets ac_find_libraries +dnl to the full name of the file that was found or leaves it empty if not found dnl --------------------------------------------------------------------------- -AC_DEFUN([WX_PATH_FIND_LIBRARIES_IN_PATH], +AC_DEFUN([WX_PATH_FIND_LIBRARIES], [ ac_find_libraries= for ac_dir in $1; @@ -60,23 +61,17 @@ AC_DEFUN([WX_PATH_FIND_LIBRARIES_IN_PATH], ]) dnl --------------------------------------------------------------------------- -dnl call WX_PATH_FIND_LIBRARIES(search path, header name), sets ac_find_libraries -dnl to the full name of the file that was found or leaves it empty if not found +dnl return list of standard library paths dnl --------------------------------------------------------------------------- -AC_DEFUN([WX_PATH_FIND_LIBRARIES], -[ - dnl check in default locations first: - dnl - /usr/lib: standard - dnl - /usr/lib32: n32 ABI on IRIX - dnl - /usr/lib64: n64 ABI on IRIX - dnl - /usr/lib/64: 64 bit ABI on Solaris and Linux x86-64 - WX_PATH_FIND_LIBRARIES_IN_PATH([/usr/lib /usr/lib32 /usr/lib/64 /usr/lib64], $2) - if test "$ac_find_libraries" != "" ; then - ac_find_libraries="default location" - else - WX_PATH_FIND_LIBRARIES_IN_PATH($1, $2) - fi -]) +dnl return all default locations: +dnl - /usr/lib: standard +dnl - /usr/lib32: n32 ABI on IRIX +dnl - /usr/lib64: n64 ABI on IRIX +dnl - /usr/lib/64: 64 bit ABI on Solaris and Linux x86-64 +dnl +dnl NB: if any of directories in the list is not a subdir of /usr, code setting +dnl wx_cv_std_libpath needs to be updated +AC_DEFUN([WX_STD_LIBPATH], [/usr/lib /usr/lib32 /usr/lib/64 /usr/lib64]) dnl --------------------------------------------------------------------------- dnl Path to include, already defined @@ -137,7 +132,7 @@ AC_DEFUN([WX_CPP_NEW_HEADERS], AC_LANG_SAVE AC_LANG_CPLUSPLUS - AC_CHECK_HEADERS(iostream) + AC_CHECK_HEADERS([iostream],,, [ ]) if test "$ac_cv_header_iostream" = "yes" ; then ifelse([$1], , :, [$1]) @@ -148,43 +143,6 @@ AC_DEFUN([WX_CPP_NEW_HEADERS], AC_LANG_RESTORE ]) -dnl --------------------------------------------------------------------------- -dnl WX_CPP_BOOL checks whether the C++ compiler has a built in bool type -dnl -dnl call WX_CPP_BOOL - will define HAVE_BOOL if the compiler supports bool -dnl --------------------------------------------------------------------------- - -AC_DEFUN([WX_CPP_BOOL], -[ - AC_CACHE_CHECK([if C++ compiler supports bool], wx_cv_cpp_bool, - [ - AC_LANG_SAVE - AC_LANG_CPLUSPLUS - - AC_TRY_COMPILE( - [ - ], - [ - bool b = true; - - return 0; - ], - [ - wx_cv_cpp_bool=yes - ], - [ - wx_cv_cpp_bool=no - ] - ) - - AC_LANG_RESTORE - ]) - - if test "$wx_cv_cpp_bool" = "yes"; then - AC_DEFINE(HAVE_BOOL) - fi -]) - dnl --------------------------------------------------------------------------- dnl WX_CPP_EXPLICIT checks whether the C++ compiler support the explicit dnl keyword and defines HAVE_EXPLICIT if this is the case @@ -232,6 +190,72 @@ AC_DEFUN([WX_CPP_EXPLICIT], fi ]) +dnl --------------------------------------------------------------------------- +dnl WX_CHECK_FUNCS(FUNCTIONS..., +dnl [ACTION-IF-FOUND], +dnl [ACTION-IF-NOT-FOUND], +dnl [EXTRA-DEFINES-AND-INCLUDES], +dnl [EXTRA-TEST-CODE]) +dnl +dnl Checks that the functions listed in FUNCTIONS exist in the headers and the +dnl libs. For each function, if it is found then defines 'HAVE_FUNCTION' and +dnl executes ACTION-IF-FOUND, otherwise executes ACTION-IF-NOT-FOUND. +dnl +dnl The code from EXTRA-DEFINES-AND-INCLUDES is inserted into the test before +dnl the default headers are included, and EXTRA-TEST-CODE is inserted into +dnl the main() function after the default test for existence. +dnl +dnl Examples: +dnl # the simple case +dnl WX_CHECK_FUNCS(stat) +dnl # use break to finish the loop early +dnl WX_CHECK_FUNCS(mkstemp mktemp, break) +dnl # extra defines +dnl WX_CHECK_FUNCS(strtok_r, [], [], [#define _RREENTRANT]) +dnl # extra includes +dnl WX_CHECK_FUNCS(swprintf, [], [], [#include ]) +dnl # checking the signature with extra test code +dnl WX_CHECK_FUNCS(gettimeofday, [], [], [#include ] +dnl [struct timeval tv; struct timezone tz; gettimeofday(&tv, &tz)]) +dnl --------------------------------------------------------------------------- + +AC_DEFUN([WX_CHECK_FUNCS], +[ + for wx_func in $1 + do + AC_CACHE_CHECK( + [for $wx_func], + [wx_cv_func_$wx_func], + [ + AC_LINK_IFELSE( + [ + AC_LANG_PROGRAM( + [ + $4 + AC_INCLUDES_DEFAULT + ], + [ + #ifndef $wx_func + &$wx_func; + #endif + $5 + ]) + ], + [eval wx_cv_func_$wx_func=yes], + [eval wx_cv_func_$wx_func=no]) + ]) + + if eval test \$wx_cv_func_$wx_func = yes + then + AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_$wx_func])) + $2 + else + : + $3 + fi + done +]) + dnl --------------------------------------------------------------------------- dnl a slightly better AC_C_BIGENDIAN macro which allows cross-compiling dnl --------------------------------------------------------------------------- @@ -271,60 +295,38 @@ fi ]) dnl --------------------------------------------------------------------------- -dnl override AC_ARG_ENABLE/WITH to cache the results in .cache file +dnl override AC_ARG_ENABLE/WITH to handle options defaults dnl --------------------------------------------------------------------------- -AC_DEFUN([WX_ARG_CACHE_INIT], - [ - wx_arg_cache_file="configarg.cache" - echo "loading argument cache $wx_arg_cache_file" - rm -f ${wx_arg_cache_file}.tmp - touch ${wx_arg_cache_file}.tmp - touch ${wx_arg_cache_file} - ]) - -AC_DEFUN([WX_ARG_CACHE_FLUSH], - [ - echo "saving argument cache $wx_arg_cache_file" - mv ${wx_arg_cache_file}.tmp ${wx_arg_cache_file} - ]) - dnl this macro checks for a three-valued command line --with argument: dnl possible arguments are 'yes', 'no', 'sys', or 'builtin' dnl usage: WX_ARG_SYS_WITH(option, helpmessage, variable-name) +dnl +dnl the default value (used if the option is not specified at all) is the value +dnl of wxUSE_ALL_FEATURES (which is "yes" by default but can be changed by +dnl giving configure --disable-all-features option) AC_DEFUN([WX_ARG_SYS_WITH], [ AC_MSG_CHECKING([for --with-$1]) - no_cache=0 AC_ARG_WITH($1, [$2], [ if test "$withval" = yes; then - ac_cv_use_$1='$3=yes' + AS_TR_SH(wx_cv_use_$1)='$3=yes' elif test "$withval" = no; then - ac_cv_use_$1='$3=no' + AS_TR_SH(wx_cv_use_$1)='$3=no' elif test "$withval" = sys; then - ac_cv_use_$1='$3=sys' + AS_TR_SH(wx_cv_use_$1)='$3=sys' elif test "$withval" = builtin; then - ac_cv_use_$1='$3=builtin' + AS_TR_SH(wx_cv_use_$1)='$3=builtin' else AC_MSG_ERROR([Invalid value for --with-$1: should be yes, no, sys, or builtin]) fi ], [ - LINE=`grep "$3" ${wx_arg_cache_file}` - if test "x$LINE" != x ; then - eval "DEFAULT_$LINE" - else - no_cache=1 - fi - - ac_cv_use_$1='$3='$DEFAULT_$3 + AS_TR_SH(wx_cv_use_$1)='$3=${'DEFAULT_$3":-$wxUSE_ALL_FEATURES}" ]) - eval "$ac_cv_use_$1" - if test "$no_cache" != 1; then - echo $ac_cv_use_$1 >> ${wx_arg_cache_file}.tmp - fi + eval "$AS_TR_SH(wx_cv_use_$1)" if test "$$3" = yes; then AC_MSG_RESULT(yes) @@ -339,85 +341,136 @@ AC_DEFUN([WX_ARG_SYS_WITH], fi ]) -dnl this macro checks for a command line argument and caches the result -dnl usage: WX_ARG_WITH(option, helpmessage, variable-name) +dnl this macro simply checks for a command line argument +dnl usage: WX_ARG_WITH(option, helpmessage, variable-name, [withstring]) AC_DEFUN([WX_ARG_WITH], [ - AC_MSG_CHECKING([for --with-$1]) - no_cache=0 + withstring=$4 + defaultval=$wxUSE_ALL_FEATURES + if test -z "$defaultval"; then + if test x"$withstring" = xwithout; then + defaultval=yes + else + defaultval=no + fi + fi + AC_MSG_CHECKING([for --${withstring:-with}-$1]) AC_ARG_WITH($1, [$2], [ if test "$withval" = yes; then - ac_cv_use_$1='$3=yes' + AS_TR_SH(wx_cv_use_$1)='$3=yes' else - ac_cv_use_$1='$3=no' + AS_TR_SH(wx_cv_use_$1)='$3=no' fi ], [ - LINE=`grep "$3" ${wx_arg_cache_file}` - if test "x$LINE" != x ; then - eval "DEFAULT_$LINE" - else - no_cache=1 - fi - - ac_cv_use_$1='$3='$DEFAULT_$3 + AS_TR_SH(wx_cv_use_$1)='$3=${'DEFAULT_$3":-$defaultval}" ]) - eval "$ac_cv_use_$1" - if test "$no_cache" != 1; then - echo $ac_cv_use_$1 >> ${wx_arg_cache_file}.tmp - fi + eval "$AS_TR_SH(wx_cv_use_$1)" - if test "$$3" = yes; then - AC_MSG_RESULT(yes) + if test x"$withstring" = xwithout; then + if test $$3 = yes; then + result=no + else + result=yes + fi else - AC_MSG_RESULT(no) + result=$$3 fi + + AC_MSG_RESULT($result) ]) +dnl same as WX_ARG_WITH but makes it clear that the option is enabled by default +AC_DEFUN([WX_ARG_WITHOUT], [WX_ARG_WITH($1, [$2], $3, without)]) + dnl like WX_ARG_WITH but uses AC_ARG_ENABLE instead of AC_ARG_WITH -dnl usage: WX_ARG_ENABLE(option, helpmessage, variable-name, enablestring) +dnl usage: WX_ARG_ENABLE(option, helpmessage, var, [enablestring], [default]) dnl -dnl enablestring is a hack and allows to show "checking for --disable-foo" -dnl message when running configure instead of the default "checking for -dnl --enable-foo" one whih is useful for the options enabled by default +dnl enablestring can be omitted or a literal string "disable" and allows to +dnl show "checking for --disable-foo" message when running configure instead of +dnl the default "checking for --enable-foo" one whih is useful for the options +dnl enabled by default +dnl +dnl the "default" argument can be omitted or contain the default value to use +dnl for the option if it's unspecified AC_DEFUN([WX_ARG_ENABLE], [ - enablestring=$4 + enablestring=$4 + defaultval=$5 + if test -z "$defaultval"; then + if test x"$enablestring" = xdisable; then + defaultval=yes + else + defaultval=no + fi + fi + AC_MSG_CHECKING([for --${enablestring:-enable}-$1]) - no_cache=0 AC_ARG_ENABLE($1, [$2], [ if test "$enableval" = yes; then - ac_cv_use_$1='$3=yes' + AS_TR_SH(wx_cv_use_$1)='$3=yes' else - ac_cv_use_$1='$3=no' + AS_TR_SH(wx_cv_use_$1)='$3=no' fi ], [ - LINE=`grep "$3" ${wx_arg_cache_file}` - if test "x$LINE" != x ; then - eval "DEFAULT_$LINE" - else - no_cache=1 - fi - - ac_cv_use_$1='$3='$DEFAULT_$3 + AS_TR_SH(wx_cv_use_$1)='$3=${'DEFAULT_$3":-$defaultval}" ]) - eval "$ac_cv_use_$1" - if test "$no_cache" != 1; then - echo $ac_cv_use_$1 >> ${wx_arg_cache_file}.tmp - fi + eval "$AS_TR_SH(wx_cv_use_$1)" - if test "$$3" = yes; then - AC_MSG_RESULT(yes) + if test x"$enablestring" = xdisable; then + if test $$3 = no; then + result=yes + else + result=no + fi else - AC_MSG_RESULT(no) + result=$$3 fi + + AC_MSG_RESULT($result) ]) +dnl the same as WX_ARG_ENABLE but makes it more clear that the option is +dnl enabled by default +AC_DEFUN([WX_ARG_DISABLE], [WX_ARG_ENABLE($1, [$2], $3, disable)]) + +dnl same as WX_ARG_ENABLE but defaults to wxUSE_ALL_FEATURES instead of "yes" +AC_DEFUN([WX_ARG_FEATURE], [WX_ARG_ENABLE($1, [$2], $3,, $wxUSE_ALL_FEATURES)]) + +dnl Like WX_ARG_ENABLE but accepts a parameter. +dnl +dnl Usage: +dnl WX_ARG_ENABLE_PARAM(option, helpmessage, variable-name, enablestring) +dnl +dnl Example: +dnl WX_ARG_ENABLE_PARAM(foo, [[ --enable-foo[=bar] use foo]], wxUSE_FOO) +dnl +dnl --enable-foo wxUSE_FOO=yes +dnl --disable-foo wxUSE_FOO=no +dnl --enable-foo=bar wxUSE_FOO=bar +dnl wxUSE_FOO=$DEFAULT_wxUSE_FOO +dnl +AC_DEFUN([WX_ARG_ENABLE_PARAM], + [ + enablestring=$4 + AC_MSG_CHECKING([for --${enablestring:-enable}-$1]) + AC_ARG_ENABLE($1, [$2], + [ + wx_cv_use_$1="$3='$enableval'" + ], + [ + wx_cv_use_$1='$3='$DEFAULT_$3 + ]) + + eval "$wx_cv_use_$1" + + AC_MSG_RESULT([$$3]) + ]) dnl =========================================================================== dnl Linker features test @@ -432,81 +485,80 @@ dnl call WX_VERSIONED_SYMBOLS(versionfile) dnl --------------------------------------------------------------------------- AC_DEFUN([WX_VERSIONED_SYMBOLS], [ - found_versioning=no - - dnl FIXME - doesn't work, Solaris linker doesn't accept wildcards - dnl in the script. - dnl dnl Check for known non-gcc cases: - dnl case "${host}" in - dnl *-*-solaris2* ) - dnl if test "x$GCC" != "xyes" ; then - dnl LDFLAGS_VERSIONING="-M $1" - dnl found_versioning=yes - dnl fi - dnl ;; - dnl esac - - dnl Generic check for GCC or GCC-like behaviour (Intel C++, GCC): - if test $found_versioning = no ; then - AC_CACHE_CHECK([if the linker accepts --version-script], wx_cv_version_script, - [ - echo "VER_1 { *; };" >conftest.sym - echo "int main() { return 0; }" >conftest.cpp - - if AC_TRY_COMMAND([ - $CXX -o conftest.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp - -Wl,--version-script,conftest.sym >/dev/null 2>conftest.stderr]) ; then - if test -s conftest.stderr ; then - wx_cv_version_script=no - else - wx_cv_version_script=yes - fi - else - wx_cv_version_script=no - fi - - dnl There's a problem in some old linkers with --version-script that - dnl can cause linking to fail when you have objects with vtables in - dnl libs 3 deep. This is known to happen in netbsd and openbsd with - dnl ld 2.11.2. - dnl - dnl To test for this we need to make some shared libs and - dnl unfortunately we can't be sure of the right way to do that. If the - dnl first two compiles don't succeed then it looks like the test isn't - dnl working and the result is ignored, but if OTOH the first two - dnl succeed but the third does not then the bug has been detected and - dnl the --version-script flag is dropped. - if test $wx_cv_version_script = yes - then - echo "struct B { virtual ~B() { } }; \ - struct D : public B { }; \ - void F() { D d; }" > conftest.cpp - - if AC_TRY_COMMAND([ - $CXX -shared -fPIC -o conftest1.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp - -Wl,--version-script,conftest.sym >/dev/null 2>/dev/null]) && - AC_TRY_COMMAND([ - $CXX -shared -fPIC -o conftest2.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp - -Wl,--version-script,conftest.sym conftest1.output >/dev/null 2>/dev/null]) - then - if AC_TRY_COMMAND([ - $CXX -shared -fPIC -o conftest3.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp - -Wl,--version-script,conftest.sym conftest2.output conftest1.output >/dev/null 2>/dev/null]) - then - wx_cv_version_script=yes - else - wx_cv_version_script=no + case "${host}" in + *-*-cygwin* | *-*-mingw* ) + dnl although ld does support version script option on these + dnl platforms, it doesn't make much sense to use it under Win32 + dnl and, moreover, this breaks linking because of a bug in handling + dnl paths in -Wl,--version-script,path option (if we ever do need + dnl to use it for cygwin/mingw32, keep in mind that replacing last + dnl comma with the equal sign works) so + dnl simply disable it + wx_cv_version_script=no + ;; + + *) + AC_CACHE_CHECK([if the linker accepts --version-script], wx_cv_version_script, + [ + echo "VER_1 { *; };" >conftest.sym + echo "int main() { return 0; }" >conftest.cpp + + if AC_TRY_COMMAND([ + $CXX -o conftest.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp + -Wl,--version-script,conftest.sym >/dev/null 2>conftest.stderr]) ; then + if test -s conftest.stderr ; then + wx_cv_version_script=no + else + wx_cv_version_script=yes + fi + else + wx_cv_version_script=no + fi + + dnl There's a problem in some old linkers with --version-script that + dnl can cause linking to fail when you have objects with vtables in + dnl libs 3 deep. This is known to happen in netbsd and openbsd with + dnl ld 2.11.2. + dnl + dnl To test for this we need to make some shared libs and + dnl unfortunately we can't be sure of the right way to do that. If the + dnl first two compiles don't succeed then it looks like the test isn't + dnl working and the result is ignored, but if OTOH the first two + dnl succeed but the third does not then the bug has been detected and + dnl the --version-script flag is dropped. + if test $wx_cv_version_script = yes + then + echo "struct B { virtual ~B() { } }; \ + struct D : public B { }; \ + void F() { D d; }" > conftest.cpp + + if AC_TRY_COMMAND([ + $CXX -shared -fPIC -o conftest1.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp + -Wl,--version-script,conftest.sym >/dev/null 2>/dev/null]) && + AC_TRY_COMMAND([ + $CXX -shared -fPIC -o conftest2.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp + -Wl,--version-script,conftest.sym conftest1.output >/dev/null 2>/dev/null]) + then + if AC_TRY_COMMAND([ + $CXX -shared -fPIC -o conftest3.output $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.cpp + -Wl,--version-script,conftest.sym conftest2.output conftest1.output >/dev/null 2>/dev/null]) + then + wx_cv_version_script=yes + else + wx_cv_version_script=no + fi + fi + fi + + rm -f conftest.output conftest.stderr conftest.sym conftest.cpp + rm -f conftest1.output conftest2.output conftest3.output + ]) + + if test $wx_cv_version_script = yes ; then + LDFLAGS_VERSIONING="-Wl,--version-script,$1" fi - fi - fi - - rm -f conftest.output conftest.stderr conftest.sym conftest.cpp - rm -f conftest1.output conftest2.output conftest3.output - ]) - if test $wx_cv_version_script = yes ; then - LDFLAGS_VERSIONING="-Wl,--version-script,$1" - fi - fi + ;; + esac ]) @@ -655,79 +707,3 @@ if test "$enable_largefile" != no; then fi ]) - -dnl Available from the GNU Autoconf Macro Archive at: -dnl http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_const_cast.html -dnl -AC_DEFUN([AC_CXX_CONST_CAST], -[AC_CACHE_CHECK(whether the compiler supports const_cast<>, -ac_cv_cxx_const_cast, -[AC_LANG_SAVE - AC_LANG_CPLUSPLUS - AC_TRY_COMPILE(,[int x = 0;const int& y = x;int& z = const_cast(y);return z;], - ac_cv_cxx_const_cast=yes, ac_cv_cxx_const_cast=no) - AC_LANG_RESTORE -]) -if test "$ac_cv_cxx_const_cast" = yes; then - AC_DEFINE(HAVE_CONST_CAST,,[define if the compiler supports const_cast<>]) -fi -]) - -dnl http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_reinterpret_cast.html -AC_DEFUN([AC_CXX_REINTERPRET_CAST], -[AC_CACHE_CHECK(whether the compiler supports reinterpret_cast<>, -ac_cv_cxx_reinterpret_cast, -[AC_LANG_SAVE - AC_LANG_CPLUSPLUS - AC_TRY_COMPILE([#include -class Base { public : Base () {} virtual void f () = 0;}; -class Derived : public Base { public : Derived () {} virtual void f () {} }; -class Unrelated { public : Unrelated () {} }; -int g (Unrelated&) { return 0; }],[ -Derived d;Base& b=d;Unrelated& e=reinterpret_cast(b);return g(e);], - ac_cv_cxx_reinterpret_cast=yes, ac_cv_cxx_reinterpret_cast=no) - AC_LANG_RESTORE -]) -if test "$ac_cv_cxx_reinterpret_cast" = yes; then - AC_DEFINE(HAVE_REINTERPRET_CAST,, - [define if the compiler supports reinterpret_cast<>]) -fi -]) - -dnl and http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_static_cast.html -AC_DEFUN([AC_CXX_STATIC_CAST], -[AC_CACHE_CHECK(whether the compiler supports static_cast<>, -ac_cv_cxx_static_cast, -[AC_LANG_SAVE - AC_LANG_CPLUSPLUS - AC_TRY_COMPILE([#include -class Base { public : Base () {} virtual void f () = 0; }; -class Derived : public Base { public : Derived () {} virtual void f () {} }; -int g (Derived&) { return 0; }],[ -Derived d; Base& b = d; Derived& s = static_cast (b); return g (s);], - ac_cv_cxx_static_cast=yes, ac_cv_cxx_static_cast=no) - AC_LANG_RESTORE -]) -if test "$ac_cv_cxx_static_cast" = yes; then - AC_DEFINE(HAVE_STATIC_CAST,, [define if the compiler supports static_cast<>]) -fi -]) - -dnl http://autoconf-archive.cryp.to/ac_cxx_dynamic_cast.html -AC_DEFUN([AC_CXX_DYNAMIC_CAST], -[AC_CACHE_CHECK(whether the compiler supports dynamic_cast<>, -ac_cv_cxx_dynamic_cast, -[AC_LANG_SAVE - AC_LANG_CPLUSPLUS - AC_TRY_COMPILE([#include -class Base { public : Base () {} virtual void f () = 0;}; -class Derived : public Base { public : Derived () {} virtual void f () {} };],[ -Derived d; Base& b=d; return dynamic_cast(&b) ? 0 : 1;], - ac_cv_cxx_dynamic_cast=yes, ac_cv_cxx_dynamic_cast=no) - AC_LANG_RESTORE -]) -if test "$ac_cv_cxx_dynamic_cast" = yes; then - AC_DEFINE(HAVE_DYNAMIC_CAST,,[define if the compiler supports dynamic_cast<>]) -fi -]) -