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Diffstat (limited to 'Build/source/texk/web2c/web2c-sh.in')
| -rw-r--r-- | Build/source/texk/web2c/web2c-sh.in | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/Build/source/texk/web2c/web2c-sh.in b/Build/source/texk/web2c/web2c-sh.in new file mode 100644 index 00000000000..368bfbf00ad --- /dev/null +++ b/Build/source/texk/web2c/web2c-sh.in @@ -0,0 +1,58 @@ +#! @SHELL@ +# web2c-sh: shell script to invoke ${srcdir}/web2c/convert. +# +# Copyright (C) 2009 Peter Breitenlohner <tex-live@tug.org> +# +# 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. +# +# Convert creates several files, e.g., FOO.c and FOO.h from FOO.p. +# The naive rule +# FOO.c FOO.h: FOO.p $(web2c_depend) +# srcdir=$(srcdir) $(SHELL) $(srcdir)/web2c/convert FOO +# could run 'convert FOO' twice in parallel and fail. To avoid this +# and yet recover from removal of FOO.c and/or FOO.h, we use an auxiliary +# stamp file FOO-web2c and the two rules +# FOO.c FOO.h: FOO-web2c +# $(SHELL) ./web2c-sh $@ FOO +# FOO-web2c: FOO.p $(web2c_depend) +# $(SHELL) ./web2c-sh $@ FOO +# Compare Automake manual (info Automake) 27.9: Multiple Outputs +# +srcdir=@srcdir@; export srcdir +target=$1 +base=$2 +stamp=$base-web2c +case $target in + $stamp) + # Normal build. + rm -f $stamp.tmp + echo timestamp >$stamp.tmp + echo "@SHELL@ $srcdir/web2c/convert $base" + @SHELL@ $srcdir/web2c/convert $base || 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 "@SHELL@ $srcdir/web2c/convert $base" + @SHELL@ $srcdir/web2c/convert $base || 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 |