Use autoconf instead of cpp for LIB_MATH.

* s/darwin.h (LIB_MATH): Do not define here, move to configure.
* s/cygwin.h (LIB_MATH): Likewise.
* Makefile.in (LIB_MATH): Do not define with cpp.
(LIBES): Use autoconf for LIB_MATH.

* configure.in (LIB_MATH): New output variable.  Set it for some systems.

configure.in

@@ -828,6 +828,20 @@ AC_LINK_IFELSE([main(){return 0;}],
   LDFLAGS=$late_LDFLAGS
   [AC_MSG_RESULT(no)])
 
+LIB_MATH=-lm
+
+case $opsys in
+  cygwin )
+    LIB_MATH=
+    ;;
+  darwin )
+    ## Adding -lm confuses the dynamic linker, so omit it.
+    LIB_MATH=
+    ;;
+esac
+
+AC_SUBST(LIB_MATH)
+
 #### Extract some information from the operating system and machine files.
 
 AC_CHECKING([the machine- and system-dependent files to find out

src/ChangeLog

+2010-04-26  Dan Nicolaescu  <dann@ics.uci.edu>
+
+	Use autoconf instead of cpp for LIB_MATH.
+	* s/darwin.h (LIB_MATH): Do not define here, move to configure.
+	* s/cygwin.h (LIB_MATH): Likewise.
+	* Makefile.in (LIB_MATH): Do not define with cpp.
+	(LIBES): Use autoconf for LIB_MATH.
+
 2010-04-26  Kenichi Handa  <handa@m17n.org>
 	* composite.c (Ffind_composition_internal): Fix the return value

src/Makefile.in

@@ -175,10 +175,6 @@ DEPFLAGS = -MMD -MF deps/$*.d
 #define LIBS_MACHINE
 #endif
 
-#ifndef LIB_MATH
-#  define LIB_MATH -lm
-#endif /* LIB_MATH */
-
 /* Some s/SYSTEM.h files define this to request special switches in ld.  */
 #ifndef LD_SWITCH_SYSTEM
 #if !defined (__GNUC__) && ((defined (BSD_SYSTEM) && !defined (COFF)))
@@ -795,7 +791,7 @@ LIBES = $(LOADLIBES) $(LIBS) $(LIBX) $(LIBSOUND) $(RSVG_LIBS) $(DBUS_LIBS) \
    @LIBGPM@ @LIBRESOLV@ LIBS_SYSTEM LIBS_MACHINE LIBS_TERMCAP \
    $(GETLOADAVG_LIBS) ${GCONF_LIBS} ${LIBSELINUX_LIBS} \
    @FREETYPE_LIBS@ @FONTCONFIG_LIBS@ @LIBOTF_LIBS@ @M17N_FLT_LIBS@ \
-   $(GNULIB_VAR) LIB_MATH LIB_STANDARD $(GNULIB_VAR)
+   $(GNULIB_VAR) @LIB_MATH@ LIB_STANDARD $(GNULIB_VAR)
 
 all: emacs${EXEEXT} $(OTHER_FILES)
 

src/s/cygwin.h

@@ -137,7 +137,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Don't list system libs on link command line */
 #define LIB_STANDARD
-#define LIB_MATH
 
 #define START_FILES ecrt0.o
 

src/s/darwin.h

@@ -205,9 +205,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* Link this program just by running cc.  */
 #define ORDINARY_LINK
 
-/* Adding -lm confuses the dynamic linker, so omit it.  */
-#define LIB_MATH
-
 /* Define the following so emacs symbols will not conflict with those
    in the System framework.  Otherwise -prebind will not work.  */