#! @SHELL@
# tangle-sh: shell script to invoke tangle (or ctangle, etc).
#
# Copyright (C) 2009 Peter Breitenlohner <
[email protected]>
#
# This file is free software; the copyright holder
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
#
# Tangle may create several files, e.g., tex.p and tex.pool from tex.web
# and tex.ch. The naive rule
# tex.p tex.pool: tex.web tex.ch tangle$(EXEEXT)
# $(tangle) tex tex
# could run 'tangle tex tex' twice in parallel and fail. To avoid this
# and yet recover from removal of tex.p and/or tex.pool, we use an
# auxiliary stamp file tex-tangle and the two rules
# tex.p tex.pool: tex-tangle
# WEBINPUTS=.:$(srcdir) $(SHELL) ./tangle-sh $@ $(TANGLE) tex tex
# tex-tangle: tex.web tex.ch tangle$(EXEEXT) tangle-sh
# WEBINPUTS=.:$(srcdir) $(SHELL) ./tangle-sh $@ $(TANGLE) tex tex
# Compare Automake manual (info Automake) 27.9: Multiple Outputs
#
TEXMFCNF=@srcdir@/../kpathsea; export TEXMFCNF
env="TEXMFCNF=$TEXMFCNF"
test "x$WEBINPUTS" = x || env="WEBINPUTS=$WEBINPUTS $env"
test "x$CWEBINPUTS" = x || env="CWEBINPUTS=$CWEBINPUTS $env"
target=$1; shift
tangle=$1; shift
base=$1
stamp=$base-tangle
case $target in
$stamp)
# Normal build.
rm -f $stamp.tmp
echo timestamp >$stamp.tmp
echo "$env $tangle $@"
$tangle "$@" || exit 1
mv -f $stamp.tmp $stamp
;;
*)
# Recover from removal of $target
test -f $target && exit 0
trap "rm -rf $stamp $stamp.lock" 1 2 13 15
if mkdir $stamp.lock 2>/dev/null; then
# Code executed by the first process.
rm -f $stamp $stamp.tmp
echo timestamp >$stamp.tmp
echo "$env $tangle $@"
$tangle "$@" || exit 1
mv -f $stamp.tmp $stamp
rmdir $stamp.lock
else
# Code executed by the follower processes.
# Wait until the first process is done.
while test -d $stamp.lock; do sleep 1; done
# Succeed if and only if the first process succeeded.
test -f $stamp; exit $?
fi
;;
esac
exit 0
