* Document output of the test.

* Libraries are in .../lib, not .../libs.
* When using AC_CHECK_LIB, the -L option has to be put into LDFLAGS
  temporarily.  Use DUNE_CHECK_LIB_EXT, which does that automatically.
* Clear the output variables if GMP was not found.
* Put result into ALL_PKG_* instead of DUNE_PKG_*

[[Imported from SVN: r5852]]

m4/gmp.m4

+## -*- autoconf -*-
+
+# DUNE_PATH_GMP()
+#
+# shell variables
+#   with_gmp
+#     no or path
+#   HAVE_GMP
+#     no or yes
+#   GMP_CPPFLAGS
+#   GMP_LIBS
+#
+# substitutions
+#   GMP_CPPFLAGS
+#   GMP_LIBS
+#
+# defines:
+#   HAVE_GMP
+#
+# conditionals:
+#   GMP
 AC_DEFUN([DUNE_PATH_GMP],[
   AC_REQUIRE([AC_PROG_CXX])
 
@@ -8,20 +29,19 @@ AC_DEFUN([DUNE_PATH_GMP],[
 
   HAVE_GMP=no
   GMP_CPPFLAGS="-I$with_gmp/include -DENABLE_GMP=1"
-  GMP_LIBS="-L$with_gmp/libs -lgmpxx -lgmp"
+  GMP_LIBS="-L$with_gmp/lib -lgmpxx -lgmp"
 
   AC_LANG_PUSH([C++])
   ac_save_CPPFLAGS="$CPPFLAGS"
   ac_save_LIBS="$LIBS"
 
   CPPFLAGS="$CPPFLAGS $GMP_CPPFLAGS"
-  LIBS="$LIBS $GMP_LIBS"
 
   AC_CHECK_HEADER([gmpxx.h], [HAVE_GMP=yes],
     AC_MSG_WARN([gmpxx.h not found in $with_gmp]))
 
   AS_IF([test $HAVE_GMP = yes],[
-    AC_CHECK_LIB(gmp,[__gmpz_abs],[],[
+    DUNE_CHECK_LIB_EXT([$with_gmp/lib], gmp,[__gmpz_abs],[],[
       HAVE_GMP=no
       AC_MSG_WARN(libgmp not found)])
   ])
@@ -32,12 +52,16 @@ AC_DEFUN([DUNE_PATH_GMP],[
 
   AS_IF([test $HAVE_GMP = yes],[
     AC_DEFINE([HAVE_GMP],[ENABLE_GMP],[Was GMP found and GMP_CPPFLAGS used?])
-    AC_SUBST([GMP_CPPFLAGS],[$GMP_CPPFLAGS])
-    AC_SUBST([GMP_LIBS],[$GMP_LIBS])
-    DUNE_PKG_CPPFLAGS="$DUNE_PKG_CPPFLAGS $GMP_CPPFLAGS"
-    DUNE_PKG_LIBS="$DUNE_PKG_LIBS $GMP_LIBS"
+    DUNE_ADD_ALL_PKG([GMP], [\${GMP_CPPFLAGS}],
+                     [], [\${GMP_LIBS}])
+  ], [
+    GMP_CPPFLAGS=
+    GMP_LIBS=
   ])
 
+  AC_SUBST([GMP_CPPFLAGS])
+  AC_SUBST([GMP_LIBS])
+
   AM_CONDITIONAL(GMP,[test $HAVE_GMP = yes])
   DUNE_ADD_SUMMARY_ENTRY([GMP],[$HAVE_GMP])
 ])