Package: automake;
Reported by: Stefano Lattarini <stefano.lattarini <at> gmail.com>
Date: Fri, 21 Jan 2011 21:21:01 UTC
Severity: normal
Tags: confirmed, help
View this message in rfc822 format
From: Stefano Lattarini <stefano.lattarini <at> gmail.com> To: automake-patches <at> gnu.org Cc: Ralf Wildenhues <Ralf.Wildenhues <at> gmx.de>, 7884 <at> debbugs.gnu.org Subject: bug#7884: [PATCH] yacc: fix VPATH builds with FreeBSD make (was: Re: bug#7884: Yacc and FreeBSD make in VPATH builds) Date: Fri, 28 Jan 2011 13:51:40 +0100
[Message part 1 (text/plain, inline)]
On Thursday 27 January 2011, Ralf Wildenhues wrote:
> Does 'make -n' create files (for any target)?
>
No, and I've updated the `yaccdry.test' testcase to also check for this
(see attached amended patch).
> How do you ensure in your patch that 'make distdir' does not create files?
>
Well, it does, but I don't see any problem with this. It's perfectly normal
for 'make distdir' to create files in the build directory, no? And anyway,
this behaviour was pre-existint with FreeBSD make, just in a much worser
form ('yacc' was used to recreate the files, instead of a simple "cp -p").
> How do you ensure in your patch that 'make clean' does not create files?
>
In fact, it does (good catch, BTW); see new testcase in the attached patch.
Yes, this is clearly a wart, but a minor one, and having it is IMHO a price
worth paying in order to have VPATH builds work on FreeBSD.
BTW, if you decide to get rid of said wart in a follow-up patch, that can
probably be done using the FreeBSD make special variable `.TARGETS' (akin
to GNU make's `MAKECMDGOALS').
Thanks,
Stefano
[0001-yacc-fix-VPATH-builds-with-FreeBSD-make.patch (text/x-patch, inline)]
From e5b393aaf4fe417e8cc8cae8056829f9083cc51c Mon Sep 17 00:00:00 2001
From: Stefano Lattarini <stefano.lattarini <at> gmail.com>
Date: Thu, 27 Jan 2011 20:30:56 +0100
Subject: [PATCH] yacc: fix VPATH builds with FreeBSD make
Fixes automake bug#7884.
* lib/am/yacc.am (.BEGIN): New target, hack to support VPATH
builds with FreeBSD make.
* automake.in (lang_yacc_target_hook): Now update the private
make variable `am__yacc_c_outputs', used by the target above.
* tests/yacc-dist-nobuild.test: Update.
* tests/yaccdry.test: Extend.
* tests/yaccvpath.test: Likewise.
* tests/yacc-d-vpath.test: Likewise.
* tests/yacc-subdir-objects-vpath.test: New test.
* tests/yacc-cond.test: Likewise.
* tests/yacc-cond-minimal.test: New test, still failing with
BSD make.
* tests/yaccdry2.test: Likewise.
* tests/Makefile.am (TESTS): Update.
---
ChangeLog | 19 +++++
automake.in | 7 ++
lib/am/yacc.am | 20 +++++
tests/Makefile.am | 4 +
tests/Makefile.in | 4 +
tests/yacc-cond-minimal.test | 81 ++++++++++++++++++++
tests/yacc-cond.test | 122 ++++++++++++++++++++++++++++++
tests/yacc-d-vpath.test | 14 ++++
tests/yacc-dist-nobuild.test | 7 +-
tests/yacc-subdir-objects-vpath.test | 137 ++++++++++++++++++++++++++++++++++
tests/yaccdry.test | 39 ++++++++++
tests/yaccdry2.test | 77 +++++++++++++++++++
tests/yaccvpath.test | 12 +++
13 files changed, 540 insertions(+), 3 deletions(-)
create mode 100755 tests/yacc-cond-minimal.test
create mode 100755 tests/yacc-cond.test
create mode 100755 tests/yacc-subdir-objects-vpath.test
create mode 100755 tests/yaccdry2.test
diff --git a/ChangeLog b/ChangeLog
index 4470c28..da291f3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,22 @@
+2011-01-28 Stefano Lattarini <stefano.lattarini <at> gmail.com>
+
+ yacc: fix VPATH builds with FreeBSD make
+ Fixes automake bug#7884.
+ * lib/am/yacc.am (.BEGIN): New target, hack to support VPATH
+ builds with FreeBSD make.
+ * automake.in (lang_yacc_target_hook): Now update the private
+ make variable `am__yacc_c_outputs', used by the target above.
+ * tests/yacc-dist-nobuild.test: Update.
+ * tests/yaccdry.test: Extend.
+ * tests/yaccvpath.test: Likewise.
+ * tests/yacc-d-vpath.test: Likewise.
+ * tests/yacc-subdir-objects-vpath.test: New test.
+ * tests/yacc-cond.test: Likewise.
+ * tests/yacc-cond-minimal.test: New test, still failing with
+ BSD make.
+ * tests/yaccdry2.test: Likewise.
+ * tests/Makefile.am (TESTS): Update.
+
2011-01-22 Stefano Lattarini <stefano.lattarini <at> gmail.com>
configure: look for a yacc program to be used by the testsuite
diff --git a/automake.in b/automake.in
index fa458d6..c72e0bc 100755
--- a/automake.in
+++ b/automake.in
@@ -6082,6 +6082,13 @@ sub lang_yacc_target_hook
}
}
+ # Required to have FreeBSD make working correctly in VPATH builds.
+ # FIXME: It would be nice to add a yacc-generated C file to
+ # $(am__yacc_c_outputs) only if it's required by the build, e.g.
+ # only if it's not declared in a false conditional ...
+ Automake::Variable::define ('am__yacc_c_outputs', VAR_AUTOMAKE, '+',
+ TRUE, $output, '', INTERNAL, VAR_PRETTY);
+
if ($yflags_contains_minus_d)
{
(my $output_base = $output) =~ s/$KNOWN_EXTENSIONS_PATTERN$//;
diff --git a/lib/am/yacc.am b/lib/am/yacc.am
index 6d35cd4..8de0edc 100644
--- a/lib/am/yacc.am
+++ b/lib/am/yacc.am
@@ -46,3 +46,23 @@ endif %?MAINTAINER-MODE%
?!GENERIC??DIST_SOURCE? $(am__skipyacc) \
## For non-suffix rules, we must emulate a VPATH search on %SOURCE%.
?!GENERIC? $(SHELL) $(YLWRAP) `test -f '%SOURCE%' || echo '$(srcdir)/'`%SOURCE% y.tab.c %OBJ% y.tab.h %BASE%.h y.output %BASE%.output -- %COMPILE%
+
+## This is releated to automake bug#7884.
+## The automake-generated Makefiles usually distribute the yacc-derived C
+## files, so that the final user won't need a working yacc to build the
+## package. But for some reason, in a VPATH build, FreeBSD make does not
+## see (or decides not to use) the yacc-derived and distributed C files
+## which are in the source directory, and tries to rebuild them (in the
+## build directory). This might fail if the user hasn't a yacc program
+## installed, or even if he has one which is uncompatible with that used
+## by the developer. So we use the following hack to ensure that, with
+## BSD make, the distributed, yacc-generated C sources are copied from
+## the source directory into the build directory, before starting the
+## "real" make operations.
+.BEGIN:
+ @for f in $(am__yacc_c_outputs); do \
+ if test ! -r $$f && test -f $(srcdir)/$$f; then \
+ echo " cp -p $(srcdir)/$$f $$f"; \
+ cp -p $(srcdir)/$$f $$f || exit 1; \
+ else :; fi; \
+ done;
diff --git a/tests/Makefile.am b/tests/Makefile.am
index e639b6c..d0e3e31 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -807,8 +807,12 @@ yacc6.test \
yacc7.test \
yacc8.test \
yaccdry.test \
+yaccdry2.test \
+yacc-cond.test \
+yacc-cond-minimal.test \
yacc-dist-nobuild.test \
yacc-nodist.test \
+yacc-subdir-objects-vpath.test \
yaccpp.test \
yaccvpath.test \
yacc-d-vpath.test \
diff --git a/tests/Makefile.in b/tests/Makefile.in
index 25fc4a8..7eca925 100644
--- a/tests/Makefile.in
+++ b/tests/Makefile.in
@@ -1075,8 +1075,12 @@ yacc6.test \
yacc7.test \
yacc8.test \
yaccdry.test \
+yaccdry2.test \
+yacc-cond.test \
+yacc-cond-minimal.test \
yacc-dist-nobuild.test \
yacc-nodist.test \
+yacc-subdir-objects-vpath.test \
yaccpp.test \
yaccvpath.test \
yacc-d-vpath.test \
diff --git a/tests/yacc-cond-minimal.test b/tests/yacc-cond-minimal.test
new file mode 100755
index 0000000..2956f01
--- /dev/null
+++ b/tests/yacc-cond-minimal.test
@@ -0,0 +1,81 @@
+#! /bin/sh
+# Copyright (C) 2011 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Check that if a yacc-generated C source or header is not needed in the
+# build tree, make won't generate not copy it there.
+
+. ./defs || Exit 1
+
+set -e
+
+cat >> configure.in << 'END'
+AM_CONDITIONAL([COND], [:])
+AC_PROG_CC
+AC_PROG_YACC
+AC_OUTPUT
+END
+
+cat > Makefile.am << 'END'
+bin_PROGRAMS = foo bar
+if COND
+foo_SOURCES = main.c
+else
+foo_SOURCES = parse.y main.c
+endif
+
+bar_SOURCES = $(foo_SOURCES)
+bar_YFLAGS = -d
+END
+
+cat > main.c << 'END'
+int main () { return 0; }
+END
+
+mkdir bin
+cat > bin/yacc <<'END'
+#!/bin/sh
+echo "$0 invoked, shouldn't happen!" >&2
+exit 1
+END
+cp bin/yacc bin/bison
+chmod a+x bin/yacc bin/bison
+PATH=`pwd`/bin$PATH_SEPARATOR$PATH
+
+YACC=yacc BISON=bison
+export YACC BISON
+
+$ACLOCAL
+$AUTOCONF
+$AUTOMAKE -a
+
+mkdir build
+cd build
+../configure
+$MAKE
+test ! -r parse.c
+test ! -r bar-parse.c
+test ! -r bar-parse.h
+$MAKE clean
+$sleep
+: > ../parse.c
+: > ../bar-parse.c
+: > ../bar-parse.h
+$MAKE
+test ! -r parse.c
+test ! -r bar-parse.c
+test ! -r bar-parse.h
+
+:
diff --git a/tests/yacc-cond.test b/tests/yacc-cond.test
new file mode 100755
index 0000000..1ebce92
--- /dev/null
+++ b/tests/yacc-cond.test
@@ -0,0 +1,122 @@
+#! /bin/sh
+# Copyright (C) 2011 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Check interaction of Yacc and conditionals.
+
+required=yacc
+. ./defs || Exit 1
+
+set -e
+
+distdir=$me-1.0
+
+cat >> configure.in << 'END'
+AM_CONDITIONAL([COND], [:])
+AC_PROG_CC
+AC_PROG_YACC
+AC_OUTPUT
+END
+
+cat > Makefile.am << 'END'
+bin_PROGRAMS = foobar zardoz
+
+AM_YFLAGS = -d
+
+if COND
+foobar_SOURCES = parse.y parse.h
+else
+foobar_SOURCES = parse.y main.c
+endif
+
+if COND
+zardoz_SOURCES = main2.c
+else
+zardoz_SOURCES = parse2.y parse2.h main2.c
+endif
+
+.PHONY: test-objs
+test-objs:
+ test -f parse.$(OBJEXT)
+ test ! -r parse2.$(OBJEXT)
+ test -f main2.$(OBJEXT)
+ test ! -r main.$(OBJEXT)
+END
+
+cat > parse2.y << 'END'
+%{
+int yylex () { return 0; }
+void yyerror (char *s) {}
+%}
+%%
+foobar : 'f' 'o' 'o' 'b' 'a' 'r' {};
+%%
+END
+
+cat > main.c << 'END'
+int main (void) { return 0; }
+END
+
+cp main.c main2.c
+
+cat parse2.y main.c > parse.y
+
+$ACLOCAL
+$AUTOCONF
+$AUTOMAKE -a
+
+./configure
+$MAKE
+ls -l
+test -f parse.c
+test -f parse.h
+test ! -r parse2.c
+test ! -r parse2.h
+$MAKE test-objs
+
+$MAKE distdir
+ls -l $distdir
+test -f $distdir/parse.c
+test -f $distdir/parse.h
+# For all we know, the `parse2.[ch]' generated files might be required by
+# the end user (if he enable the COND conditional), so we must distribute
+# them.
+test -f $distdir/parse2.c
+test -f $distdir/parse2.h
+
+# Now check that yacc is not needed to build from a distribution tarball.
+
+chmod -R a-w $distdir
+
+mkdir bin
+cat > bin/yacc <<'END'
+#!/bin/sh
+echo "$0 invoked, shouldn't happen!" >&2
+exit 1
+END
+cp bin/yacc bin/bison
+chmod a+x bin/yacc bin/bison
+PATH=`pwd`/bin$PATH_SEPARATOR$PATH
+
+YACC=yacc BISON=bison
+export YACC BISON
+
+mkdir build
+cd build
+../$distdir/configure
+$MAKE
+$MAKE test-objs
+
+:
diff --git a/tests/yacc-d-vpath.test b/tests/yacc-d-vpath.test
index bb09990..4d2fed8 100755
--- a/tests/yacc-d-vpath.test
+++ b/tests/yacc-d-vpath.test
@@ -109,4 +109,18 @@ $MAKE distdir
$FGREP maude $distdir/parse.c
$FGREP MAUDE $distdir/parse.h
+# Now check that `make maintainer-clean' removes all yacc-derived
+# files (if any) created in the builddir. Try it two times, to
+# be stricter in face of possible `.BEGIN' targets executed by BSD
+# make.
+cp config.status config.sav
+$MAKE maintainer-clean
+test ! -r parse.c
+test ! -r parse.h
+# Recreate Makefile, depfiles, etc.
+mv -f config.sav config.status; ./config.status
+$MAKE maintainer-clean
+test ! -r parse.c
+test ! -r parse.h
+
:
diff --git a/tests/yacc-dist-nobuild.test b/tests/yacc-dist-nobuild.test
index 9061f57..26f5924 100755
--- a/tests/yacc-dist-nobuild.test
+++ b/tests/yacc-dist-nobuild.test
@@ -79,9 +79,10 @@ cd build
$MAKE
# Sanity check.
-chmod u+w ../$distdir
-rm -f ../$distdir/parse.c
-chmod a-w ../$distdir
+$sleep
+chmod u+w ../$distdir/parse.y
+echo >> ../$distdir/parse.y
+chmod a-w ../$distdir/parse.y
$MAKE >out 2>&1 && { cat out; Exit 1; }
cat out
$FGREP parse.c out
diff --git a/tests/yacc-subdir-objects-vpath.test b/tests/yacc-subdir-objects-vpath.test
new file mode 100755
index 0000000..c427e47
--- /dev/null
+++ b/tests/yacc-subdir-objects-vpath.test
@@ -0,0 +1,137 @@
+#! /bin/sh
+# Copyright (C) 2011 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Some tests for subdir parsers in VPATH builds.
+# See also test `yacc8.test'.
+
+required=yacc
+. ./defs || Exit 1
+
+set -e
+
+cat >> configure.in << 'END'
+AC_PROG_CC
+AM_PROG_CC_C_O
+AC_PROG_YACC
+AC_OUTPUT
+END
+
+cat > Makefile.am << 'END'
+AUTOMAKE_OPTIONS = subdir-objects
+bin_PROGRAMS = foo/bar baz/qux
+foo_bar_SOURCES = foo/parse.y
+baz_qux_SOURCES = baz/parse.y baz/main.c baz/parse.h
+AM_YFLAGS = -d
+
+.PHONY: test-com test1 test2
+test-com:
+ ls -l . foo $(srcdir) $(srcdir)/foo
+ test ! -r parse.h
+ test ! -r parse.c
+ test ! -r parse.$(OBJEXT)
+ test -f foo/parse.$(OBJEXT)
+ test -f baz/parse.$(OBJEXT)
+test1: test-com
+ test -f foo/parse.c
+ test -f foo/parse.h
+ test -f baz/parse.c
+ test -f baz/parse.h
+test2: test-com
+ test -f $(srcdir)/foo/parse.c
+ test -f $(srcdir)/foo/parse.h
+ test -f $(srcdir)/baz/parse.c
+ test -f $(srcdir)/baz/parse.h
+END
+
+mkdir foo
+cat > foo/parse.y << 'END'
+%{
+int yylex () { return 0; }
+void yyerror (char *s) { return; }
+%}
+%%
+x : 'x' {};
+%%
+int main (void) { return 0; }
+END
+
+mkdir baz
+cat > baz/parse.y << 'END'
+%{
+int yylex () { return 0; }
+void yyerror (char *s) { return; }
+%}
+%token BAZBAZ
+%%
+x : 'x' {};
+%%
+END
+cat > baz/main.c << 'END'
+#include "baz/parse.h"
+int main (void)
+{
+ return (BAZBAZ);
+}
+END
+
+$ACLOCAL
+$AUTOCONF
+$AUTOMAKE -a
+
+# Try a from-scratch VPATH build.
+mkdir sub1
+cd sub1
+../configure
+$MAKE
+$MAKE test1
+
+# Also, let's see if we can recover from removal of generated header
+# files.
+rm -f foo/parse.h baz/parse.h
+$MAKE foo/parse.h baz/parse.h
+test -f foo/parse.h
+test -f baz/parse.h
+$MAKE clean
+rm -f foo/parse.h baz/parse.h
+$MAKE
+test -f baz/parse.h
+# foo/parse.h is not declares in any *_SOURCES, nor #included by any
+# C file, so that it shouldn't be rebuilt by "make all".
+test ! -r foo/parse.h
+
+cd ..
+
+# Generate yacc-derived files with an in-tree build.
+./configure
+$MAKE foo/parse.c foo/parse.h baz/parse.c baz/parse.h
+$MAKE distclean
+ls -l . foo
+test -f foo/parse.c
+test -f foo/parse.h
+test -f baz/parse.c
+test -f baz/parse.h
+
+# Now try a VPATH build with yacc-generated files already present in
+# the srcdir.
+YACC=false BISON=false
+export YACC BISON
+mkdir sub2
+cd sub2
+../configure
+$MAKE
+$MAKE test2
+
+:
diff --git a/tests/yaccdry.test b/tests/yaccdry.test
index d30fb80..8eebc67 100755
--- a/tests/yaccdry.test
+++ b/tests/yaccdry.test
@@ -21,6 +21,8 @@ required=yacc
set -e
+distdir=$me-1.0
+
cat >> configure.in << 'END'
AC_PROG_CC
AC_PROG_YACC
@@ -49,12 +51,49 @@ END
$ACLOCAL
$AUTOMAKE --add-missing
$AUTOCONF
+
+# Try an in-tree build first.
+
./configure
$MAKE
rm -f parse.h
+
+$MAKE -n
+test -f parse.c
+test ! -f parse.h
+
$MAKE -n parse.h
test -f parse.c
test ! -f parse.h
+# Now try VPATH build.
+
+$MAKE distdir
+mkdir build
+cd build
+../$distdir/configure
+
+$MAKE -n
+test ! -f parse.c
+test ! -f parse.h
+
+$MAKE -n parse.h
+test ! -f parse.c
+test ! -f parse.h
+
+rm -f ../$distdir/parse.h
+
+$MAKE -n
+test ! -f parse.c
+test ! -f parse.h
+test ! -f ../$distdir/parse.h
+test -f ../$distdir/parse.c
+
+$MAKE -n parse.h
+test ! -f parse.c
+test ! -f parse.h
+test ! -f ../$distdir/parse.h
+test -f ../$distdir/parse.c
+
:
diff --git a/tests/yaccdry2.test b/tests/yaccdry2.test
new file mode 100755
index 0000000..22902af
--- /dev/null
+++ b/tests/yaccdry2.test
@@ -0,0 +1,77 @@
+#! /bin/sh
+# Copyright (C) 2011 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Check that, in a VPATH build, no yacc-derived C file is created in
+# the build directory by targets like "make clean".
+
+. ./defs || Exit 1
+
+set -e
+
+unset YACC || :
+
+distdir=$me-1.0
+
+cat > my-yacc <<'END'
+#!/bin/sh
+echo 'int main () { return 0; }' > y.tab.c
+: > y.tab.h
+END
+chmod a+x my-yacc
+
+cat >> configure.in << 'END'
+AC_PROG_CC
+AC_SUBST([YACC], ['$(abs_builddir)/my-yacc'])
+AC_OUTPUT
+END
+
+cat > Makefile.am << 'END'
+AM_YFLAGS = -d
+bin_PROGRAMS = foo
+foo_SOURCES = parse.y
+END
+
+: > parse.y
+
+$ACLOCAL
+$AUTOMAKE --add-missing
+$AUTOCONF
+
+# From-scratch VPATH build.
+mkdir build-scratch
+cd build-scratch
+../configure
+for target in mostlyclean clean distclean; do
+ $MAKE $target
+ test ! -f parse.c
+ test ! -f parse.h
+done
+
+cd ..
+./configure
+$MAKE distdir
+
+# VPATH build from distributed tarball.
+mkdir build-dist
+cd build-dist
+../$distdir/configure
+for target in mostlyclean clean distclean; do
+ $MAKE $target
+ test ! -f parse.c
+ test ! -f parse.h
+done
+
+:
diff --git a/tests/yaccvpath.test b/tests/yaccvpath.test
index 52092fa..853c5df 100755
--- a/tests/yaccvpath.test
+++ b/tests/yaccvpath.test
@@ -99,4 +99,16 @@ END
$MAKE distdir
$FGREP maude $distdir/parse.c
+# Now check that `make maintainer-clean' removes all yacc-derived
+# files (if any) created in the builddir. Try it two times, to
+# be stricter in face of possible `.BEGIN' targets executed by BSD
+# make.
+cp config.status config.sav
+$MAKE maintainer-clean
+test ! -r parse.c
+# Recreate Makefile, depfiles, etc.
+mv -f config.sav config.status; ./config.status
+$MAKE maintainer-clean
+test ! -r parse.c
+
:
--
1.7.2.3
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.