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Index: cacao-0.98/configure.ac
===================================================================
--- cacao-0.98.orig/configure.ac 2007-07-21 12:11:47.000000000 +0200
+++ cacao-0.98/configure.ac 2007-07-21 13:36:40.000000000 +0200
@@ -234,6 +234,48 @@
AC_EGREP_HEADER(u_int32_t, sys/types.h, AC_DEFINE(HAVE_BSD_INT32_DEFINED, 1, [Define to 1 if you have BSD u_int32_t]))
AC_EGREP_HEADER(u_int32_t, sys/config.h, AC_DEFINE(HAVE_BSD_INT32_DEFINED, 1, [Define to 1 if you have BSD u_int32_t]))
+dnl The idea of this solutions comes from bochs-project configure.in
+dnl
+dnl Add the -lm library if math functions cannot be used without it.
+dnl This check is important on cygwin because of the bizarre way that they
+dnl have organized functions into libraries. On cygwin, both libc.a and
+dnl libm.a are symbolic links to a single lib libcygwin.a. This means that
+dnl 1) linking with -lm is not necessary, and
+dnl 2) linking with -lm is dangerous if the order of libraries is wrong
+dnl In particular, if you compile any program with -mno-cygwin and link with
+dnl -lm, it will crash instantly when it is run. This happens because the
+dnl linker incorrectly links the Cygwin libm.a (==libcygwin.a), which replaces
+dnl the ___main function instead of allowing it to be defined by
+dnl /usr/lib/mingw/libmingw32.a as it should be.
+dnl
+dnl On MacOS X, this test will find that -lm is unnecessary and leave it out.
+dnl
+dnl With uClibc and without libjvm cacao needs to be linked with -lm because of
+dnl the function scalbn
+dnl
+dnl Just check this math functions. If it is found without
+dnl -lm, then we must not need -lm.
+have_scalbn=0
+AC_CHECK_FUNCS(scalbn, have_scalbn=1)
+AC_MSG_CHECKING(if math functions link without -lm)
+if test "$have_scalbn" = 1; then
+ AC_MSG_RESULT(yes)
+else
+ AC_MSG_RESULT(no)
+ LIBS="$LIBS -lm"
+ # use different functions to bypass configure caching
+ have_scalbl=0
+ AC_CHECK_FUNCS(scalbl, have_scalbl=1)
+ AC_MSG_CHECKING(if math functions link with -lm)
+ if test "$have_scalbl" = 1; then
+ AC_MSG_RESULT(yes)
+ else
+ AC_MSG_RESULT(no)
+ # not sure we should warn the user, crash, etc.
+ # expect link failure
+ fi
+fi
+
dnl Checks for typedefs, structures, and compiler characteristics.
AC_C_CONST
AC_C_INLINE
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