Index: driver/cfa.cc
===================================================================
--- driver/cfa.cc	(revision 851fd922c452a3693f22ace8775f19ea83de680a)
+++ driver/cfa.cc	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -385,9 +385,14 @@
 	} // if
 
+	string preludedir;
 	switch(path) {
-	case Installed   : Putenv( argv, "--prelude-dir=" + libdir ); break;
-	case BuildTree   : Putenv( argv, "--prelude-dir=" + libdir + "/prelude" ); break;
-	case Distributed : Putenv( argv, "--prelude-dir=" + dir(argv[0]) ); break;
+	case Installed   : preludedir = libdir; break;
+	case BuildTree   : preludedir = libdir + "/prelude"; break;
+	case Distributed : preludedir = dir(argv[0]); break;
 	}
+
+	Putenv( argv, "--prelude-dir=" + preludedir );
+	args[nargs++] = "-include";
+	args[nargs++] = (*new string(preludedir + "/defines.hfa")).c_str();
 
 	for ( int i = 0; i < nlibs; i += 1 ) {				// copy non-user libraries after all user libraries
Index: libcfa/Makefile.in
===================================================================
--- libcfa/Makefile.in	(revision 851fd922c452a3693f22ace8775f19ea83de680a)
+++ libcfa/Makefile.in	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -106,4 +106,5 @@
  configure.lineno config.status.lineno
 mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = $(top_builddir)/prelude/defines.hfa
 CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
Index: libcfa/configure
===================================================================
--- libcfa/configure	(revision 851fd922c452a3693f22ace8775f19ea83de680a)
+++ libcfa/configure	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -16966,4 +16966,7 @@
 
 
+ac_config_headers="$ac_config_headers prelude/defines.hfa"
+
+
 cat >confcache <<\_ACEOF
 # This file is a shell script that caches the results of configure
@@ -17056,41 +17059,5 @@
 test "x$exec_prefix" = xNONE && exec_prefix='${prefix}'
 
-# Transform confdefs.h into DEFS.
-# Protect against shell expansion while executing Makefile rules.
-# Protect against Makefile macro expansion.
-#
-# If the first sed substitution is executed (which looks for macros that
-# take arguments), then branch to the quote section.  Otherwise,
-# look for a macro that doesn't take arguments.
-ac_script='
-:mline
-/\\$/{
- N
- s,\\\n,,
- b mline
-}
-t clear
-:clear
-s/^[	 ]*#[	 ]*define[	 ][	 ]*\([^	 (][^	 (]*([^)]*)\)[	 ]*\(.*\)/-D\1=\2/g
-t quote
-s/^[	 ]*#[	 ]*define[	 ][	 ]*\([^	 ][^	 ]*\)[	 ]*\(.*\)/-D\1=\2/g
-t quote
-b any
-:quote
-s/[	 `~#$^&*(){}\\|;'\''"<>?]/\\&/g
-s/\[/\\&/g
-s/\]/\\&/g
-s/\$/$$/g
-H
-:any
-${
-	g
-	s/^\n//
-	s/\n/ /g
-	p
-}
-'
-DEFS=`sed -n "$ac_script" confdefs.h`
-
+DEFS=-DHAVE_CONFIG_H
 
 ac_libobjs=
@@ -17570,4 +17537,7 @@
 esac
 
+case $ac_config_headers in *"
+"*) set x $ac_config_headers; shift; ac_config_headers=$*;;
+esac
 
 
@@ -17575,4 +17545,5 @@
 # Files that config.status was made for.
 config_files="$ac_config_files"
+config_headers="$ac_config_headers"
 config_commands="$ac_config_commands"
 
@@ -17596,7 +17567,12 @@
       --file=FILE[:TEMPLATE]
                    instantiate the configuration file FILE
+      --header=FILE[:TEMPLATE]
+                   instantiate the configuration header FILE
 
 Configuration files:
 $config_files
+
+Configuration headers:
+$config_headers
 
 Configuration commands:
@@ -17666,5 +17642,16 @@
     as_fn_append CONFIG_FILES " '$ac_optarg'"
     ac_need_defaults=false;;
-  --he | --h |  --help | --hel | -h )
+  --header | --heade | --head | --hea )
+    $ac_shift
+    case $ac_optarg in
+    *\'*) ac_optarg=`$as_echo "$ac_optarg" | sed "s/'/'\\\\\\\\''/g"` ;;
+    esac
+    as_fn_append CONFIG_HEADERS " '$ac_optarg'"
+    ac_need_defaults=false;;
+  --he | --h)
+    # Conflict between --help and --header
+    as_fn_error $? "ambiguous option: \`$1'
+Try \`$0 --help' for more information.";;
+  --help | --hel | -h )
     $as_echo "$ac_cs_usage"; exit ;;
   -q | -quiet | --quiet | --quie | --qui | --qu | --q \
@@ -18113,4 +18100,5 @@
     "src/Makefile") CONFIG_FILES="$CONFIG_FILES src/Makefile" ;;
     "prelude/Makefile") CONFIG_FILES="$CONFIG_FILES prelude/Makefile" ;;
+    "prelude/defines.hfa") CONFIG_HEADERS="$CONFIG_HEADERS prelude/defines.hfa" ;;
 
   *) as_fn_error $? "invalid argument: \`$ac_config_target'" "$LINENO" 5;;
@@ -18125,4 +18113,5 @@
 if $ac_need_defaults; then
   test "${CONFIG_FILES+set}" = set || CONFIG_FILES=$config_files
+  test "${CONFIG_HEADERS+set}" = set || CONFIG_HEADERS=$config_headers
   test "${CONFIG_COMMANDS+set}" = set || CONFIG_COMMANDS=$config_commands
 fi
@@ -18313,6 +18302,114 @@
 fi # test -n "$CONFIG_FILES"
 
-
-eval set X "  :F $CONFIG_FILES      :C $CONFIG_COMMANDS"
+# Set up the scripts for CONFIG_HEADERS section.
+# No need to generate them if there are no CONFIG_HEADERS.
+# This happens for instance with `./config.status Makefile'.
+if test -n "$CONFIG_HEADERS"; then
+cat >"$ac_tmp/defines.awk" <<\_ACAWK ||
+BEGIN {
+_ACEOF
+
+# Transform confdefs.h into an awk script `defines.awk', embedded as
+# here-document in config.status, that substitutes the proper values into
+# config.h.in to produce config.h.
+
+# Create a delimiter string that does not exist in confdefs.h, to ease
+# handling of long lines.
+ac_delim='%!_!# '
+for ac_last_try in false false :; do
+  ac_tt=`sed -n "/$ac_delim/p" confdefs.h`
+  if test -z "$ac_tt"; then
+    break
+  elif $ac_last_try; then
+    as_fn_error $? "could not make $CONFIG_HEADERS" "$LINENO" 5
+  else
+    ac_delim="$ac_delim!$ac_delim _$ac_delim!! "
+  fi
+done
+
+# For the awk script, D is an array of macro values keyed by name,
+# likewise P contains macro parameters if any.  Preserve backslash
+# newline sequences.
+
+ac_word_re=[_$as_cr_Letters][_$as_cr_alnum]*
+sed -n '
+s/.\{148\}/&'"$ac_delim"'/g
+t rset
+:rset
+s/^[	 ]*#[	 ]*define[	 ][	 ]*/ /
+t def
+d
+:def
+s/\\$//
+t bsnl
+s/["\\]/\\&/g
+s/^ \('"$ac_word_re"'\)\(([^()]*)\)[	 ]*\(.*\)/P["\1"]="\2"\
+D["\1"]=" \3"/p
+s/^ \('"$ac_word_re"'\)[	 ]*\(.*\)/D["\1"]=" \2"/p
+d
+:bsnl
+s/["\\]/\\&/g
+s/^ \('"$ac_word_re"'\)\(([^()]*)\)[	 ]*\(.*\)/P["\1"]="\2"\
+D["\1"]=" \3\\\\\\n"\\/p
+t cont
+s/^ \('"$ac_word_re"'\)[	 ]*\(.*\)/D["\1"]=" \2\\\\\\n"\\/p
+t cont
+d
+:cont
+n
+s/.\{148\}/&'"$ac_delim"'/g
+t clear
+:clear
+s/\\$//
+t bsnlc
+s/["\\]/\\&/g; s/^/"/; s/$/"/p
+d
+:bsnlc
+s/["\\]/\\&/g; s/^/"/; s/$/\\\\\\n"\\/p
+b cont
+' <confdefs.h | sed '
+s/'"$ac_delim"'/"\\\
+"/g' >>$CONFIG_STATUS || ac_write_fail=1
+
+cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
+  for (key in D) D_is_set[key] = 1
+  FS = ""
+}
+/^[\t ]*#[\t ]*(define|undef)[\t ]+$ac_word_re([\t (]|\$)/ {
+  line = \$ 0
+  split(line, arg, " ")
+  if (arg[1] == "#") {
+    defundef = arg[2]
+    mac1 = arg[3]
+  } else {
+    defundef = substr(arg[1], 2)
+    mac1 = arg[2]
+  }
+  split(mac1, mac2, "(") #)
+  macro = mac2[1]
+  prefix = substr(line, 1, index(line, defundef) - 1)
+  if (D_is_set[macro]) {
+    # Preserve the white space surrounding the "#".
+    print prefix "define", macro P[macro] D[macro]
+    next
+  } else {
+    # Replace #undef with comments.  This is necessary, for example,
+    # in the case of _POSIX_SOURCE, which is predefined and required
+    # on some systems where configure will not decide to define it.
+    if (defundef == "undef") {
+      print "/*", prefix defundef, macro, "*/"
+      next
+    }
+  }
+}
+{ print }
+_ACAWK
+_ACEOF
+cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
+  as_fn_error $? "could not setup config headers machinery" "$LINENO" 5
+fi # test -n "$CONFIG_HEADERS"
+
+
+eval set X "  :F $CONFIG_FILES  :H $CONFIG_HEADERS    :C $CONFIG_COMMANDS"
 shift
 for ac_tag
@@ -18533,5 +18630,62 @@
   || as_fn_error $? "could not create $ac_file" "$LINENO" 5
  ;;
-
+  :H)
+  #
+  # CONFIG_HEADER
+  #
+  if test x"$ac_file" != x-; then
+    {
+      $as_echo "/* $configure_input  */" \
+      && eval '$AWK -f "$ac_tmp/defines.awk"' "$ac_file_inputs"
+    } >"$ac_tmp/config.h" \
+      || as_fn_error $? "could not create $ac_file" "$LINENO" 5
+    if diff "$ac_file" "$ac_tmp/config.h" >/dev/null 2>&1; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: $ac_file is unchanged" >&5
+$as_echo "$as_me: $ac_file is unchanged" >&6;}
+    else
+      rm -f "$ac_file"
+      mv "$ac_tmp/config.h" "$ac_file" \
+	|| as_fn_error $? "could not create $ac_file" "$LINENO" 5
+    fi
+  else
+    $as_echo "/* $configure_input  */" \
+      && eval '$AWK -f "$ac_tmp/defines.awk"' "$ac_file_inputs" \
+      || as_fn_error $? "could not create -" "$LINENO" 5
+  fi
+# Compute "$ac_file"'s index in $config_headers.
+_am_arg="$ac_file"
+_am_stamp_count=1
+for _am_header in $config_headers :; do
+  case $_am_header in
+    $_am_arg | $_am_arg:* )
+      break ;;
+    * )
+      _am_stamp_count=`expr $_am_stamp_count + 1` ;;
+  esac
+done
+echo "timestamp for $_am_arg" >`$as_dirname -- "$_am_arg" ||
+$as_expr X"$_am_arg" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
+	 X"$_am_arg" : 'X\(//\)[^/]' \| \
+	 X"$_am_arg" : 'X\(//\)$' \| \
+	 X"$_am_arg" : 'X\(/\)' \| . 2>/dev/null ||
+$as_echo X"$_am_arg" |
+    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)[^/].*/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\/\)$/{
+	    s//\1/
+	    q
+	  }
+	  /^X\(\/\).*/{
+	    s//\1/
+	    q
+	  }
+	  s/.*/./; q'`/stamp-h$_am_stamp_count
+ ;;
 
   :C)  { $as_echo "$as_me:${as_lineno-$LINENO}: executing $ac_file commands" >&5
Index: libcfa/configure.ac
===================================================================
--- libcfa/configure.ac	(revision 851fd922c452a3693f22ace8775f19ea83de680a)
+++ libcfa/configure.ac	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -126,4 +126,6 @@
 	])
 
+AC_CONFIG_HEADERS(prelude/defines.hfa)
+
 AC_OUTPUT()
 
Index: libcfa/prelude/Makefile.am
===================================================================
--- libcfa/prelude/Makefile.am	(revision 851fd922c452a3693f22ace8775f19ea83de680a)
+++ libcfa/prelude/Makefile.am	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -21,5 +21,5 @@
 # put into lib for now
 cfalibdir = ${CFA_LIBDIR}
-cfalib_DATA = gcc-builtins.cf builtins.cf extras.cf prelude.cfa bootloader.c
+cfalib_DATA = gcc-builtins.cf builtins.cf extras.cf prelude.cfa bootloader.c defines.hfa
 
 CC = @LOCAL_CFACC@
Index: libcfa/prelude/Makefile.in
===================================================================
--- libcfa/prelude/Makefile.in	(revision 851fd922c452a3693f22ace8775f19ea83de680a)
+++ libcfa/prelude/Makefile.in	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -104,4 +104,5 @@
 DIST_COMMON = $(srcdir)/Makefile.am $(am__DIST_COMMON)
 mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = defines.hfa
 CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
@@ -154,6 +155,25 @@
 am__installdirs = "$(DESTDIR)$(cfalibdir)"
 DATA = $(cfalib_DATA)
-am__tagged_files = $(HEADERS) $(SOURCES) $(TAGS_FILES) $(LISP)
-am__DIST_COMMON = $(srcdir)/Makefile.in
+am__tagged_files = $(HEADERS) $(SOURCES) $(TAGS_FILES) \
+	$(LISP)defines.hfa.in
+# Read a list of newline-separated strings from the standard input,
+# and print each of them once, without duplicates.  Input order is
+# *not* preserved.
+am__uniquify_input = $(AWK) '\
+  BEGIN { nonempty = 0; } \
+  { items[$$0] = 1; nonempty = 1; } \
+  END { if (nonempty) { for (i in items) print i; }; } \
+'
+# Make sure the list of sources is unique.  This is necessary because,
+# e.g., the same source file might be shared among _SOURCES variables
+# for different programs/libraries.
+am__define_uniq_tagged_files = \
+  list='$(am__tagged_files)'; \
+  unique=`for i in $$list; do \
+    if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
+  done | $(am__uniquify_input)`
+ETAGS = etags
+CTAGS = ctags
+am__DIST_COMMON = $(srcdir)/Makefile.in $(srcdir)/defines.hfa.in
 DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
 ACLOCAL = @ACLOCAL@
@@ -306,10 +326,11 @@
 # put into lib for now
 cfalibdir = ${CFA_LIBDIR}
-cfalib_DATA = gcc-builtins.cf builtins.cf extras.cf prelude.cfa bootloader.c
+cfalib_DATA = gcc-builtins.cf builtins.cf extras.cf prelude.cfa bootloader.c defines.hfa
 AM_CFLAGS = -g -Wall -Wno-unused-function -fPIC @ARCH_FLAGS@ @CONFIG_CFLAGS@
 AM_CFAFLAGS = @CONFIG_CFAFLAGS@
 MOSTLYCLEANFILES = bootloader.c builtins.cf extras.cf gcc-builtins.c gcc-builtins.cf prelude.cfa
 MAINTAINERCLEANFILES = ${addprefix ${libdir}/,${cfalib_DATA}} ${addprefix ${libdir}/,${lib_LIBRARIES}}
-all: all-am
+all: defines.hfa
+	$(MAKE) $(AM_MAKEFLAGS) all-am
 
 .SUFFIXES:
@@ -344,4 +365,19 @@
 $(am__aclocal_m4_deps):
 
+defines.hfa: stamp-h1
+	@test -f $@ || rm -f stamp-h1
+	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) stamp-h1
+
+stamp-h1: $(srcdir)/defines.hfa.in $(top_builddir)/config.status
+	@rm -f stamp-h1
+	cd $(top_builddir) && $(SHELL) ./config.status prelude/defines.hfa
+$(srcdir)/defines.hfa.in:  $(am__configure_deps) 
+	($(am__cd) $(top_srcdir) && $(AUTOHEADER))
+	rm -f stamp-h1
+	touch $@
+
+distclean-hdr:
+	-rm -f defines.hfa stamp-h1
+
 mostlyclean-libtool:
 	-rm -f *.lo
@@ -370,10 +406,56 @@
 	files=`for p in $$list; do echo $$p; done | sed -e 's|^.*/||'`; \
 	dir='$(DESTDIR)$(cfalibdir)'; $(am__uninstall_files_from_dir)
-tags TAGS:
-
-ctags CTAGS:
-
-cscope cscopelist:
-
+
+ID: $(am__tagged_files)
+	$(am__define_uniq_tagged_files); mkid -fID $$unique
+tags: tags-am
+TAGS: tags
+
+tags-am: $(TAGS_DEPENDENCIES) $(am__tagged_files)
+	set x; \
+	here=`pwd`; \
+	$(am__define_uniq_tagged_files); \
+	shift; \
+	if test -z "$(ETAGS_ARGS)$$*$$unique"; then :; else \
+	  test -n "$$unique" || unique=$$empty_fix; \
+	  if test $$# -gt 0; then \
+	    $(ETAGS) $(ETAGSFLAGS) $(AM_ETAGSFLAGS) $(ETAGS_ARGS) \
+	      "$$@" $$unique; \
+	  else \
+	    $(ETAGS) $(ETAGSFLAGS) $(AM_ETAGSFLAGS) $(ETAGS_ARGS) \
+	      $$unique; \
+	  fi; \
+	fi
+ctags: ctags-am
+
+CTAGS: ctags
+ctags-am: $(TAGS_DEPENDENCIES) $(am__tagged_files)
+	$(am__define_uniq_tagged_files); \
+	test -z "$(CTAGS_ARGS)$$unique" \
+	  || $(CTAGS) $(CTAGSFLAGS) $(AM_CTAGSFLAGS) $(CTAGS_ARGS) \
+	     $$unique
+
+GTAGS:
+	here=`$(am__cd) $(top_builddir) && pwd` \
+	  && $(am__cd) $(top_srcdir) \
+	  && gtags -i $(GTAGS_ARGS) "$$here"
+cscopelist: cscopelist-am
+
+cscopelist-am: $(am__tagged_files)
+	list='$(am__tagged_files)'; \
+	case "$(srcdir)" in \
+	  [\\/]* | ?:[\\/]*) sdir="$(srcdir)" ;; \
+	  *) sdir=$(subdir)/$(srcdir) ;; \
+	esac; \
+	for i in $$list; do \
+	  if test -f "$$i"; then \
+	    echo "$(subdir)/$$i"; \
+	  else \
+	    echo "$$sdir/$$i"; \
+	  fi; \
+	done >> $(top_builddir)/cscope.files
+
+distclean-tags:
+	-rm -f TAGS ID GTAGS GRTAGS GSYMS GPATH tags
 
 distdir: $(DISTFILES)
@@ -409,5 +491,5 @@
 check-am: all-am
 check: check-am
-all-am: Makefile $(DATA)
+all-am: Makefile $(DATA) defines.hfa
 installdirs:
 	for dir in "$(DESTDIR)$(cfalibdir)"; do \
@@ -452,5 +534,5 @@
 distclean: distclean-am
 	-rm -f Makefile
-distclean-am: clean-am distclean-generic
+distclean-am: clean-am distclean-generic distclean-hdr distclean-tags
 
 dvi: dvi-am
@@ -513,9 +595,10 @@
 uninstall-am: uninstall-cfalibDATA
 
-.MAKE: install-am install-strip
-
-.PHONY: all all-am check check-am clean clean-generic clean-libtool \
-	cscopelist-am ctags-am distclean distclean-generic \
-	distclean-libtool distdir dvi dvi-am html html-am info info-am \
+.MAKE: all install-am install-strip
+
+.PHONY: CTAGS GTAGS TAGS all all-am check check-am clean clean-generic \
+	clean-libtool cscopelist-am ctags ctags-am distclean \
+	distclean-generic distclean-hdr distclean-libtool \
+	distclean-tags distdir dvi dvi-am html html-am info info-am \
 	install install-am install-cfalibDATA install-data \
 	install-data-am install-dvi install-dvi-am install-exec \
@@ -526,5 +609,5 @@
 	maintainer-clean-generic maintainer-clean-local mostlyclean \
 	mostlyclean-generic mostlyclean-libtool pdf pdf-am ps ps-am \
-	tags-am uninstall uninstall-am uninstall-cfalibDATA
+	tags tags-am uninstall uninstall-am uninstall-cfalibDATA
 
 .PRECIOUS: Makefile
Index: libcfa/prelude/defines.hfa.in
===================================================================
--- libcfa/prelude/defines.hfa.in	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
+++ libcfa/prelude/defines.hfa.in	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -0,0 +1,2 @@
+
+#undef HAVE_LINUX_IO_URING_H
Index: libcfa/src/Makefile.in
===================================================================
--- libcfa/src/Makefile.in	(revision 851fd922c452a3693f22ace8775f19ea83de680a)
+++ libcfa/src/Makefile.in	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -105,4 +105,5 @@
 	$(am__nobase_cfa_include_HEADERS_DIST) $(am__DIST_COMMON)
 mkinstalldirs = $(install_sh) -d
+CONFIG_HEADER = $(top_builddir)/prelude/defines.hfa
 CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
@@ -194,5 +195,5 @@
 am__v_at_0 = @
 am__v_at_1 = 
-DEFAULT_INCLUDES = -I.@am__isrc@
+DEFAULT_INCLUDES = -I.@am__isrc@ -I$(top_builddir)/prelude
 depcomp = $(SHELL) $(top_srcdir)/automake/depcomp
 am__depfiles_maybe = depfiles
Index: tools/build/push2dist.sh
===================================================================
--- tools/build/push2dist.sh	(revision 851fd922c452a3693f22ace8775f19ea83de680a)
+++ tools/build/push2dist.sh	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -19,5 +19,5 @@
 # echo "Copying to machines : ${hosts} (hash=${hash})"
 
-files="../../../driver/cfa ../../../driver/cfa-cpp ../../../driver/cc1 ../../../driver/as $(find . -name '*.c*' | tr '\n' ' ')"
+files="../../../driver/cfa ../../../driver/cfa-cpp ../../../driver/cc1 ../../../driver/as defines.hfa $(find . -name '*.c*' | tr '\n' ' ')"
 # echo "Files ${files}"