* configure.in: support C level backtrace information on FreeBSD.

When devel/libexecinfo is installed on FreeBSD, now ruby
  can show C level backtrace information.
  http://www.freebsd.org/cgi/cvsweb.cgi/ports/devel/libexecinfo/

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29768 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Fri Nov 12 16:35:31 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* configure.in: support C level backtrace information on FreeBSD.
+	  When devel/libexecinfo is installed on FreeBSD, now ruby
+	  can show C level backtrace information.
+	  http://www.freebsd.org/cgi/cvsweb.cgi/ports/devel/libexecinfo/
+
 Fri Nov 12 09:58:30 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* win32/setup.mak: use findstr.exe instead of find.exe, because all

configure.in

@@ -1800,6 +1800,15 @@ main(int argc, char *argv[])
     test x$rb_cv_fork_with_pthread = xyes || AC_DEFINE(CANNOT_FORK_WITH_PTHREAD)
 fi
 
+AS_CASE(["$target_os"],
+[freebsd*], [
+    AC_CHECK_HEADERS([/usr/local/include/execinfo.h])
+    if test "x$ac_cv_header__usr_local_include_execinfo_h" = xyes; then :
+	RUBY_APPEND_OPTION(CPPFLAGS, -I/usr/local/include)
+	LDFLAGS="${LDFLAGS:+$LDFLAGS }-L/usr/local/lib"
+	DLDFLAGS="${DLDFLAGS:+$DLDFLAGS }-L/usr/local/lib"
+	AC_CHECK_LIB([execinfo], [backtrace])
+    fi])
 AC_CHECK_FUNCS(backtrace)
 
 AC_ARG_WITH(valgrind,