Clarify error message (Trac #3805)

[ghc-hetmet.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index fa5f9a3..bc5c62b 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -296,7 +296,7 @@ checkVendor() {
 
 checkOS() {
     case $1 in
-    linux|freebsd|netbsd|openbsd|dragonfly|osf1|osf3|hpux|linuxaout|kfreebsdgnu|freebsd2|solaris2|cygwin32|mingw32|darwin|gnu|nextstep2|nextstep3|sunos4|ultrix|irix|aix)
+    linux|freebsd|netbsd|openbsd|dragonfly|osf1|osf3|hpux|linuxaout|kfreebsdgnu|freebsd2|solaris2|cygwin32|mingw32|darwin|gnu|nextstep2|nextstep3|sunos4|ultrix|irix|aix|haiku)
         ;;
     *)
         echo "Unknown OS '$1'"
@@ -723,18 +723,19 @@ if test $HaveLibMingwEx = YES ; then
   AC_DEFINE([HAVE_MINGWEX], [1], [Define to 1 if you have the mingwex library.])
 fi
 
+dnl ** check for math library
+dnl    Keep that check as early as possible.
+dnl    as we need to know whether we need libm
+dnl    for math functions or not
+dnl    (see http://hackage.haskell.org/trac/ghc/ticket/3730)
+AC_SEARCH_LIBS(atan, m, 
+  [AC_DEFINE([HAVE_LIBM], [1], [Define to 1 if you need to link with libm])])
+
 dnl ** check whether this machine has BFD and liberty installed (used for debugging)
 dnl    the order of these tests matters: bfd needs liberty
 AC_CHECK_LIB(iberty, xmalloc)
 AC_CHECK_LIB(bfd,    bfd_init)
 
-dnl ** check for math library
-AC_CHECK_FUNC(atan,[fp_libm_not_needed=yes;LIBM=],[fp_libm_not_needed=dunno])
-if test x"$fp_libm_not_needed" = xdunno; then
-   AC_CHECK_LIB([m], [atan], [LIBS="-lm $LIBS"; LIBM="-lm"],[LIBM=])
-fi
-AC_SUBST([LIBM])
-
 dnl ################################################################
 dnl Check for libraries
 dnl ################################################################