(GNU_CPP_PREDEFINES): New macro.

From-SVN: r8948

gcc/config/gnu.h

 /* Configuration common to all targets running the GNU system.  */
 
+/* Macro to produce CPP_PREDEFINES for GNU on a given machine.  */
+#define GNU_CPP_PREDEFINES(machine) \
+"-D" machine " -Acpu(" machine ") -Amachine(" machine ")"
+"-Dunix -Asystem(unix) \
+-DMACH -Asystem(mach) \
+-D__GNU__ -Asystem(gnu) -D__HURD__"
+
 /* Provide GCC options for standard feature-test macros.  */
 #undef CPP_SPEC
 #define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{bsd:-D_BSD_SOURCE}"