bench: check impact of %debug on variants.

* etc/bench.pl.in (variant_grammar): Fix the computation of
	$variant.
	Generate a grammar file that can work with or without %debug.
	Do use the @directive.
	(bench_variant_parser): Check impact of %debug.
	(@directives): Rename all the occurrences to...
	(@directive): this, for consistency.

etc/bench.pl.in

@@ -119,9 +119,9 @@ not a valid directive.
 
 sub directives($@)
 {
-  my ($bench, @directives) = @_;
+  my ($bench, @directive) = @_;
   my $res = "/* Directives for bench `$bench'. */\n";
-  for my $d (@directives)
+  for my $d (@directive)
     {
       $res .= $d . "\n"
         unless $d eq '%variant';
@@ -130,7 +130,7 @@ sub directives($@)
   return $res;
 }
 
-=item C<triangular_grammar ($base, $max, @directives)>
+=item C<triangular_grammar ($base, $max, @directive)>
 
 Create a large triangular grammar which looks like :
 
@@ -150,7 +150,7 @@ Create a large triangular grammar which looks like :
 
 C<$base> is the base name for the file to create (F<$base.y>).
 C<$max> is the number of such rules (here, 5).  You may pass
-additional Bison C<@directives>.
+additional Bison C<@directive>.
 
 The created parser is self contained: it includes its scanner, and
 source of input.
@@ -158,8 +158,8 @@ source of input.
 
 sub triangular_grammar ($$$)
 {
-  my ($base, $max, @directives) = @_;
-  my $directives = directives ($base, @directives);
+  my ($base, $max, @directive) = @_;
+  my $directives = directives ($base, @directive);
 
   my $out = new IO::File ">$base.y"
     or die;
@@ -267,18 +267,18 @@ sub calc_input ($$)
 }
 
 ##################################################################
-=item C<calc_grammar ($base, $max, @directives)>
+=item C<calc_grammar ($base, $max, @directive)>
 
 Generate a Bison file F<$base.y> for a calculator parser in C.  Pass
-the additional Bison C<@directives>.  C<$max> is ignored, but left to
+the additional Bison C<@directive>.  C<$max> is ignored, but left to
 have the same interface as C<triangular_grammar>.
 
 =cut
 
 sub calc_grammar ($$$)
 {
-  my ($base, $max, @directives) = @_;
-  my $directives = directives ($base, @directives);
+  my ($base, $max, @directive) = @_;
+  my $directives = directives ($base, @directive);
 
   my $out = new IO::File ">$base.y"
     or die;
@@ -477,32 +477,32 @@ EOF
 
 ##################################################################
 
-=item C<variant_grammar ($base, $max, @directives)>
+=item C<variant_grammar ($base, $max, @directive)>
 
 Generate a Bison file F<$base.y> that uses, or not, the Boost.Variants
-depending on the C<@directives>.
+depending on the C<@directive>.
 
 =cut
 
 sub variant_grammar ($$$)
 {
-  my ($base, $max, @directives) = @_;
-  my $directives = directives ($base, @directives);
-  my $variant = grep { '%variant' } @directives;
+  my ($base, $max, @directive) = @_;
+  my $directives = directives ($base, @directive);
+  my $variant = grep { $_ eq '%variant' } @directive;
 
   my $out = new IO::File ">$base.y"
     or die;
   print $out <<EOF;
-%debug
 %language "C++"
 %defines
+$directives
 
-%code requires // code for the .hh file
+%code requires // variant.h
 {
 #include <string>
 }
 
-%code // code for the .cc file
+%code // variant.c
 {
 #include <algorithm>
 #include <iostream>
@@ -612,7 +612,9 @@ yy::parser::error(const yy::parser::location_type& yylloc,
 int main(int argc, char *argv[])
 {
   yy::parser p;
+#if YYDEBUG
   p.set_debug_level(!!getenv("YYDEBUG"));
+#endif
   p.parse();
   return 0;
 }
@@ -647,9 +649,9 @@ sub compile ($)
 Generate benches for C<$gram>.  C<$gram> should be C<calc> or
 C<triangle>.  C<%bench> is a hash of the form:
 
-  $name => @directives
+  $name => @directive
 
-where C<$name> is the name of the bench, and C<@directives> are the
+where C<$name> is the name of the bench, and C<@directive> are the
 Bison directive to use for this bench.  All the benches are compared
 against each other, repeated 50 times.
 
@@ -671,6 +673,7 @@ sub bench_grammar ($%)
       # Call the Bison input file generator.
       my $generator = "$gram" . "_grammar";
       &$generator ($name, 200, @$directives);
+      # Compile the executable.
       compile ($name);
       $bench{$name} = "system ('./$name');";
       chop($size{$name} = `wc -c <$name`);
@@ -732,8 +735,10 @@ sub bench_variant_parser ()
   bench_grammar
     ('variant',
      (
-      "union"    => [],
-      "variant"  => ['%variant'],
+      "union"         => [],
+      "variant"       => ['%variant'],
+      "union-debug"   => ['%debug'],
+      "variant-debug" => ['%debug', '%variant'],
      )
     );
 }