Clean up spkg-configure.m4 for mpc to follow the current model for mpc

build/pkgs/mpc/spkg-configure.m4

@@ -1,50 +1,20 @@
 SAGE_SPKG_CONFIGURE([mpc], [
-    AC_ARG_WITH([mpc],
-    [AS_HELP_STRING([--with-mpc=system],
-        [use the system MPC, if possible (default)])]
-    [AS_HELP_STRING([--with-mpc=install],
-        [use the Sage SPKG for MPC])])
-
-dnl Just part the options here
-    case "$with_mpc" in
-        system) ;;
-        install) ;;
-        "") with_mpc=system;;
-        *)
-            AC_MSG_ERROR([allowed values for --with-mpc are system and install]);;
-    esac
-    
-    case "$with_mpc" in
-        system)
-            AC_CHECK_HEADER(mpc.h, [], [sage_spkg_install_mpc=yes])
+    AC_REQUIRE([SAGE_SPKG_CONFIGURE_MPFR])
+    AC_MSG_CHECKING([installing mpfr? ])
+    if test x$sage_spkg_install_mpfr = xyes; then
+        AC_MSG_RESULT([yes; install mpc as well])
+        sage_spkg_install_mpc=yes
+    else
+        AC_CHECK_HEADER(mpc.h, [], [sage_spkg_install_mpc=yes])
         dnl mpc_cmp_abs appeared in MPC 1.1.0
-            AC_SEARCH_LIBS([mpc_cmp_abs], [mpc], [break], [sage_spkg_install_mpc=yes])
-
-            if test x$sage_spkg_install_mpc = xyes; then
-               AC_SUBST(SAGE_MPC_PREFIX, ['$SAGE_LOCAL'])
-           dnl AC_SUBST(SAGE_MPC_INCLUDE, ['$SAGE_LOCAL/include']) --- not used
-               AC_MSG_RESULT([using Sage's mpc SPKG])
-            else
-           dnl If found, we want to get the absolute path to where we
-           dnl found it for use with some packages want
-           dnl this information at configure time
-               AX_ABSOLUTE_HEADER([mpc.h])
-               if test x$gl_cv_absolute_mpc_h = x; then
-                   AC_MSG_ERROR(m4_normalize([
-                     failed to find absolute path to mpc.h despite it being reported found
-                   ]))
-               fi
-           dnl AC_SUBST(SAGE_MPC_INCLUDE, [`AS_DIRNAME($gl_cv_absolute_mpc_h)`])
-               AC_SUBST(SAGE_MPC_PREFIX, [''])
-               AC_MSG_RESULT([using mpc library from the system])
-            fi
-            ;;
-        install)
-            sage_spkg_install_mpc=yes
-            AC_SUBST(SAGE_MPC_PREFIX, ['$SAGE_LOCAL'])
-        dnl AC_SUBST(SAGE_MPC_INCLUDE, ['$SAGE_LOCAL/include'])
-            AC_MSG_RESULT([using Sage's mpc SPKG])
-            ;;
-    esac
-
+        AC_SEARCH_LIBS([mpc_cmp_abs], [mpc], [break], [sage_spkg_install_mpc=yes])
+    fi
+], [], [], [
+    if test x$sage_spkg_install_mpc = xyes; then
+        AC_SUBST(SAGE_MPC_PREFIX, ['$SAGE_LOCAL'])
+        AC_MSG_RESULT([using Sage's mpc SPKG])
+    else
+       AC_SUBST(SAGE_MPC_PREFIX, [''])
+       AC_MSG_RESULT([using mpc library from the system])
+    fi
 ])