xlat: extend syntax

* xlat/gen.sh: Implement #stop directive that stops preprocessor
at the line it has been encountered during the first pass.  This could
be used, for example, to provide fallback definitions for constants
without defining xlat tables.

diff --git a/xlat/gen.sh b/xlat/gen.sh
index ec632803a23818e005147e85242f7cfa9f745654..d3dec2aa809cd6770f55a12f50b6c35294197fa2 100755 (executable)
--- a/xlat/gen.sh
+++ b/xlat/gen.sh
@@ -135,6 +135,9 @@ gen_header()
        while read line; do
                LC_COLLATE=C
                case $line in
+               '#stop')
+                       exit 0
+                       ;;
                '#conditional')
                        unconditional=
                        ;;