Improve GRECS_SETUP.

The macro takes an optional second argument.  When given, it supplies
the name of the preprocessor setup file to install.

Options available for use in the 1st argument are:

no-preproc              Generate the --without-preprocessor option.
std-pp-setup            Install the default pp-setup file.  Note for
                        upgraders: earlier this was the default!
pp-setup-option         Generate the --with-pp-setup-file option.

* am/grecs.m4 (GRECS_SETUP): Handle new options.

1 files changed, 58 insertions, 6 deletions

diff --git a/am/grecs.m4 b/am/grecs.m4
index 72c6432..dfed409 100644
--- a/am/grecs.m4
+++ b/am/grecs.m4
@@ -1,4 +1,4 @@
-# This file is part of grecs - Gray's Extensible Configuration System
+# This file is part of grecs - Gray's Extensible Configuration System -*- autoconf -*-
 # Copyright (C) 2007, 2009, 2010 Sergey Poznyakoff
 #
 # Grex is free software; you can redistribute it and/or modify
@@ -14,12 +14,48 @@
 # You should have received a copy of the GNU General Public License
 # along with Grex.  If not, see <http://www.gnu.org/licenses/>.
 
-# GRECS_SETUP([no-preproc])
+# _GRECS_MANGLE_OPTION(NAME)
+# -------------------------
+# Convert NAME to a valid m4 identifier, by replacing invalid characters
+# with underscores, and prepend the _GRECS_OPTION_ suffix to it.
+AC_DEFUN([_GRECS_MANGLE_OPTION],
+[[_GRECS_OPTION_]m4_bpatsubst($1, [[^a-zA-Z0-9_]], [_])])
+
+# _GRECS_SET_OPTION(NAME)
+# ----------------------
+# Set option NAME. 
+AC_DEFUN([_GRECS_SET_OPTION],
+[m4_define(_GRECS_MANGLE_OPTION([$1]), 1)])
+
+# _GRECS_IF_OPTION_SET(NAME,IF-SET,IF-NOT-SET)
+# -------------------------------------------
+# Check if option NAME is set.
+AC_DEFUN([_GRECS_IF_OPTION_SET],
+[m4_ifset(_GRECS_MANGLE_OPTION([$1]),[$2],[$3])])
+
+# _GRECS_OPTION_SWITCH(NAME1,IF-SET1,[NAME2,IF-SET2,[...]],[IF-NOT-SET])
+# ------------------------------------------------------------------------
+# If NAME1 is set, run IF-SET1.  Otherwise, if NAME2 is set, run IF-SET2.
+# Continue the process for all name-if-set pairs within [...].  If none
+# of the options is set, run IF-NOT-SET.
+AC_DEFUN([_GRECS_OPTION_SWITCH],
+[m4_if([$4],,[_GRECS_IF_OPTION_SET($@)],dnl
+[$3],,[_GRECS_IF_OPTION_SET($@)],dnl
+[_GRECS_IF_OPTION_SET([$1],[$2],[_GRECS_OPTION_SWITCH(m4_shift(m4_shift($@)))])])])
+
+# _GRECS_SET_OPTIONS(OPTIONS)
+# ----------------------------------
+# OPTIONS is a space-separated list of Gint options.
+AC_DEFUN([_GRECS_SET_OPTIONS],
+[m4_foreach_w([_GRECS_Option], [$1], [_GRECS_SET_OPTION(_GRECS_Option)])])
+
+# GRECS_SETUP([no-preproc std-pp-setup pp-setup-option],[pp-setup-file])
 AC_DEFUN([GRECS_SETUP],[
+  _GRECS_SET_OPTIONS([$1])
   # **********************	
   # Preprocessor
   # **********************
-  m4_if($1,[no-preproc],
+  _GRECS_IF_OPTION_SET([no-preproc],  
         [use_ext_pp=no],
         [AC_ARG_WITH([preprocessor],
 		      AC_HELP_STRING([--without-preprocessor],
@@ -48,9 +84,25 @@ AC_DEFUN([GRECS_SETUP],[
     DEFAULT_PREPROCESSOR=$PPBIN
     if test -n "$DEFAULT_PREPROCESSOR"; then
       DEFAULT_PREPROCESSOR="$DEFAULT_PREPROCESSOR $PREPROC_OPTIONS"
-      case $PPBIN in
-        *m4) AC_SUBST(PP_SETUP_FILE,'pp-setup');; # Install default pp-setup
-      esac
+      _GRECS_IF_OPTION_SET([std-pp-setup],
+        [PP_SETUP_FILE='pp-setup'],
+	[m4_if([$2],,[PP_SETUP_FILE=],[PP_SETUP_FILE='$2'])])
+      AC_SUBST(PP_SETUP_FILE)
+      if test -n "$PP_SETUP_FILE"; then
+        _GRECS_IF_OPTION_SET([pp-setup-option],
+	  [AC_ARG_WITH([pp-setup-file],
+		      AC_HELP_STRING([--with-pp-setup-file],
+				     [install the default pp-setup file]),
+	   [case "${withval}" in
+	    yes) ;;
+	    no)  PP_SETUP_FILE=;;
+	    *)   AC_MSG_ERROR([bad value ${withval} for --with-pp-setup-file]) ;;
+	    esac])],
+	  [case $PPBIN in
+           *m4) ;; # Install default pp-setup
+	   *) PP_SETUP_FILE=;; # Skip it
+           esac])
+      fi
     fi
     PATH=$save_PATH
     DEFAULT_PREPROCESSOR="\\\"$DEFAULT_PREPROCESSOR\\\""