xml: beware of user strings used to give a %prec to rules.

[bison.git] / doc / local.mk

diff --git a/doc/local.mk b/doc/local.mk
index d13979049f67edb464875f0c4421beb978fc7983..cf68a98ab8a1616fa91bb82e40431f3c2f63d043 100644 (file)
--- a/doc/local.mk
+++ b/doc/local.mk
@@ -1,5 +1,5 @@
-## Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007, 2008 Free Software
-## Foundation, Inc.
+## Copyright (C) 2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009
+## 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
@@ -29,11 +29,14 @@ clean-local:
 CROSS_OPTIONS_PL = $(top_srcdir)/build-aux/cross-options.pl
 CROSS_OPTIONS_TEXI = $(top_srcdir)/doc/cross-options.texi
 $(CROSS_OPTIONS_TEXI): $(top_srcdir)/src/getargs.c $(CROSS_OPTIONS_PL)
-       mv -f $@ $@~ || : >$@~
-       -rm -f $@.tmp
+# Create $@~ which is the previous contents.  Don't use `mv' here so
+# that even if we are interrupted, the file is still available for
+# diff in the next run.  Note that $@ might not exist yet.
+       { test ! -f $@ || cat $@; } >$@~
+       test ! -f $@.tmp || rm -f $@.tmp
        $(MAKE) $(AM_MAKEFLAGS) src/bison$(EXEEXT)
-       $(top_builddir)/src/bison --help |                              \
-       perl $(CROSS_OPTIONS_PL) $(top_srcdir)/src/scan-gram.l >$@.tmp
+       $(top_builddir)/src/bison --help |                               \
+         perl $(CROSS_OPTIONS_PL) $(top_srcdir)/src/scan-gram.l >$@.tmp
        diff -u $@~ $@.tmp || true
        mv $@.tmp $@
 MAINTAINERCLEANFILES = $(CROSS_OPTIONS_TEXI)