ylwrap proposition & fix

[Sergey Poznyakoff]

Hi!

I would propose to add an option to ylwrap specifying the replacement
sequence for yy prefix in identifiers. For example if you'd run:

  sh ylwrap bison gram.y y.tab.c gram.c y.tab.h gram.h -- -yy foo_ -d

then all the yy.* identifiers in output files gram.c and gram.h would
become: foo_.*, so that yyparse would become foo_parse, etc. This
will simplify including multiple grammars in a program. The aproach
seems to be more convenient than `#define yyparse c_parse' approach
proposed by automake.info. Of course the same functionality can
be achieved by -p option to bison, but some yaccs don't understand
it ...

The patch below implements this and also fixes an inconsistency in
handling `#line ' statements, due to which `#line 54 "/src/gram.y'
became `#line 54 "/gram.y"' (leading slash confuses gdb).

Regards,
Sergey Poznyakoff

Index: ylwrap
===================================================================
RCS file: /cvs/automake/lib/ylwrap,v
retrieving revision 1.16
diff -p -u -w -b -r1.16 ylwrap
--- ylwrap      2001/05/15 03:33:20     1.16
+++ ylwrap      2001/06/08 10:19:37
@@ -18,12 +18,13 @@
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 # Usage:
-#     ylwrap PROGRAM [ARGS] INPUT [OUTPUT DESIRED]... -- [ARGS]...
+#     ylwrap PROGRAM [ARGS] INPUT [OUTPUT DESIRED]... -- [-yy repl] [ARGS]...
 # * PROGRAM is program to run; options can follow but must start with `-'.
 # * INPUT is the input file
 # * OUTPUT is file PROG generates
 # * DESIRED is file we actually want
 # * ARGS are passed to PROG
+# * Optional -yy introduces the sequence to replace yy prefixes with.
 # Any number of OUTPUT,DESIRED pairs may be used.
 
 # The program to run.
@@ -81,6 +82,18 @@ while test "$#" -ne 0; do
    shift
 done
 
+if [ $# -ne 0 ]; then
+    if [ "x$1" = "x-yy" ]; then
+       shift
+       if [ $# -eq 0 ]; then 
+               echo "ylwrap: -yy requires an argument"
+               exit 1 
+       fi
+       YYREPL=$1
+       shift
+    fi
+fi    
+
 # FIXME: add hostname here for parallel makes that run commands on
 # other machines.  But that might take us over the 14-char limit.
 dirname=ylwrap$$
@@ -128,7 +141,11 @@ if test $status -eq 0; then
         # resulting debug information to point at an absolute srcdir;
         # it is better for it to just mention the .y file with no
         # path.
-        sed -e "/^#/ s,$input_rx,," "$from" > "$target" || status=$?
+        EXPR="/^#/ s,$input_rx/,,"
+        if [ ! -z "$YYREPL" ]; then
+           EXPR="$EXPR;s/yy/$YYREPL/g"
+        fi
+        sed -e "$EXPR" "$from" > "$target" || status=$?
       else
         # A missing file is only an error for the first file.  This
         # is a blatant hack to let us support using "yacc -d".  If -d