Fix configury where most compilers will get mislabeled as 'gnu'.

Most compilers define the __GNU__ macro, so put it at the bottom
as a catch-all.

Tested with gcc, xlc, pgi and clang.

Signed-off-by: Austen Lauria <[email protected]>

Author: awlauria

config/opal_check_vendor.m4

@@ -132,30 +132,6 @@ AC_DEFUN([_OPAL_CHECK_COMPILER_VENDOR], [
                ],
                [OPAL_IF_IFELSE([defined(_AIX) && !defined(__GNUC__)],
                     [opal_check_compiler_vendor_result="ibm"])])])
-
-    # GNU
-    AS_IF([test "$opal_check_compiler_vendor_result" = "unknown"],
-          [OPAL_IFDEF_IFELSE([__GNUC__],
-               [opal_check_compiler_vendor_result="gnu"
-
-               # We do not support gccfss as a compiler so die if
-               # someone tries to use said compiler.  gccfss (gcc
-               # for SPARC Systems) is a compiler that is no longer
-               # supported by Oracle and it has some major flaws
-               # that prevents it from actually compiling OMPI code.
-               # So if we detect it we automatically bail.
-
-               if ($CC --version | grep gccfss) >/dev/null 2>&1; then
-                   AC_MSG_RESULT([gccfss])
-                   AC_MSG_WARN([Detected gccfss being used to compile Open MPI.])
-                   AC_MSG_WARN([Because of several issues Open MPI does not support])
-                   AC_MSG_WARN([the gccfss compiler.  Please use a different compiler.])
-                   AC_MSG_WARN([If you did not think you used gccfss you may want to])
-                   AC_MSG_WARN([check to see if the compiler you think you used is])
-                   AC_MSG_WARN([actually a link to gccfss.])
-                   AC_MSG_ERROR([Cannot continue])
-               fi])])
-
     # Borland Turbo C
     AS_IF([test "$opal_check_compiler_vendor_result" = "unknown"],
           [OPAL_IFDEF_IFELSE([__TURBOC__],
@@ -279,6 +255,29 @@ AC_DEFUN([_OPAL_CHECK_COMPILER_VENDOR], [
           [OPAL_IFDEF_IFELSE([__WATCOMC__],
                [opal_check_compiler_vendor_result="watcom"])])
 
+    # GNU
+    AS_IF([test "$opal_check_compiler_vendor_result" = "unknown"],
+          [OPAL_IFDEF_IFELSE([__GNUC__],
+               [opal_check_compiler_vendor_result="gnu"
+
+               # We do not support gccfss as a compiler so die if
+               # someone tries to use said compiler.  gccfss (gcc
+               # for SPARC Systems) is a compiler that is no longer
+               # supported by Oracle and it has some major flaws
+               # that prevents it from actually compiling OMPI code.
+               # So if we detect it we automatically bail.
+
+               if ($CC --version | grep gccfss) >/dev/null 2>&1; then
+                   AC_MSG_RESULT([gccfss])
+                   AC_MSG_WARN([Detected gccfss being used to compile Open MPI.])
+                   AC_MSG_WARN([Because of several issues Open MPI does not support])
+                   AC_MSG_WARN([the gccfss compiler.  Please use a different compiler.])
+                   AC_MSG_WARN([If you did not think you used gccfss you may want to])
+                   AC_MSG_WARN([check to see if the compiler you think you used is])
+                   AC_MSG_WARN([actually a link to gccfss.])
+                   AC_MSG_ERROR([Cannot continue])
+               fi])])
+
     $1="$opal_check_compiler_vendor_result"
     unset opal_check_compiler_vendor_result
 ])