Re: push parser

[Joel E. Denny]

On Mon, 18 Dec 2006, Joel E. Denny wrote:

> > This will break a lot of code, I'm afraid, since many apps assume
> > yyparse is a true function and is not a macro.
>
> No apps assume that for %push-parser since no apps use %push-parser yet.

> > While we're on the subject, the "&yylex" isn't portable either.  yylex
> > might be a macro, or it might not have exactly the signature you
> > expect (it might return 'wchar_t', say).
> 
> Thanks.  Bummer.  Again, we'd need something like %pull-parser.

I decided to try out something along those lines.  Here are some 
advantages:

1. Using a lexer function pointer can have a measurable negative impact on 
performance (especially when I pass -O3 to gcc), so in this regard it's 
better to hard-code the yylex call.  (If the user actually wants the 
flexibility to call multiple lexer functions, he can write his own 
yypush_parse wrappers.  This wasn't actually one of my objectives in the 
existing implementation anyway.)

2. If the user wishes to define yylex as a macro, that can have an 
additional measurable positive impact on performance, so we should 
probably allow that for yyparse in push mode.

3. I believe that making yyparse a function rather than a macro will make 
the push mode interface completely compatible with the pull mode 
interface.  This should simplify the documentation and the test suite.  I 
still want yypull_parse since it can be mixed with yypush_parse, and I see 
no harm to performance by adding this function to the call chain.  This 
makes sense since yyparse and/or yypull_parse are called only once per 
parse.

At the moment, I favor:

  %push-pull-parser

rather than:

  %push-parser
  %pull-parser

The latter begs the question: what does %pull-parser do when there's no 
%push-parser?  Moreover, the former is shorter.

What do people think of the following uncommitted patch?

Index: ChangeLog
===================================================================
RCS file: /sources/bison/bison/ChangeLog,v
retrieving revision 1.1639
diff -p -u -r1.1639 ChangeLog
--- ChangeLog   26 Dec 2006 18:09:53 -0000      1.1639
+++ ChangeLog   26 Dec 2006 23:47:57 -0000
@@ -1,5 +1,45 @@
 2006-12-26  Joel E. Denny  <address@hidden>
 
+       For push mode, convert yyparse from a macro to a function, invoke yylex
+       instead of passing a yylexp argument to yypull_parse, and don't
+       generate yypull_parse or yyparse unless %push-pull-parser is declared.
+       Discussed starting at
+       <http://lists.gnu.org/archive/html/bison-patches/2006-12/msg00163.html>.
+       * data/bison.m4 (b4_pull_if): New.
+       * data/c.m4 (YYPULL): New similar to YYPUSH.
+       * data/push.c: Improve M4 quoting a little.
+       (b4_generate_macro_args, b4_parenthesize): Remove.
+       (yyparse): If there's a b4_prefix, #define this to b4_prefix[parse]
+       any time a pull parser is requested.
+       Don't #define this as a wrapper around yypull_parse.  Instead, when
+       both push and pull are requested, make it a function that does that
+       same thing.
+       (yypull_parse): If there's a b4_prefix, #define this to
+       b4_prefix[pull_parse] when both push and pull are requested.
+       Don't define this as a function unless both push and pull are
+       requested.
+       Remove the yylexp argument and hard-code yylex invocation instead.
+       * etc/bench.pl.in (bench_grammar): Use %push-pull-parser instead of
+       %push-parser.
+       * src/getargs.c (pull_parser): New global initialized to true.
+       * getargs.h (pull_parser): extern it.
+       * src/output.c (prepare): Insert pull_flag muscle.
+       * src/parse-gram.y (PERCENT_PUSH_PULL_PARSER): New token.
+       (prologue_declaration): Set both push_parser and pull_parser = true for
+       %push-pull-parser.  Set push_parser = true and pull_parser = false for
+       %push-parser.
+       * src/scan-gram.l: Don't accept %push_parser as an alternative to
+       %push-parser since there's no backward-compatibility concern here.
+       Scan %push-pull-parser.
+       * tests/calc.at (Simple LALR(1) Calculator): Use %push-pull-parser
+       instead of %push-parser.
+       * tests/headers.at (export YYLTYPE): Make yylex static, and don't
+       prototype it in the module that calls yyparse.
+       * tests/input.at (Torturing the Scanner): Likewise.
+       * tests/local.at (AT_PUSH_IF): Check for %push-pull-parser as well.
+
+2006-12-26  Joel E. Denny  <address@hidden>
+
        Update etc/bench.pl.  Optimize push mode a little (the yyn change
        deserves most of the credit).
        * Makefile.am (SUBDIRS): Add etc subdirectory.
Index: data/bison.m4
===================================================================
RCS file: /sources/bison/bison/data/bison.m4,v
retrieving revision 1.2
diff -p -u -r1.2 bison.m4
--- data/bison.m4       15 Oct 2006 12:37:06 -0000      1.2
+++ data/bison.m4       26 Dec 2006 23:47:57 -0000
@@ -127,8 +127,9 @@ b4_define_flag_if([error_verbose])  # Whe
 b4_define_flag_if([glr])               # Whether a GLR parser is requested.
 b4_define_flag_if([locations])         # Whether locations are tracked.
 b4_define_flag_if([nondeterministic])  # Whether conflicts should be handled.
+b4_define_flag_if([pull])              # Whether pull parsing is requested.
 b4_define_flag_if([pure])              # Whether the interface is pure.
-b4_define_flag_if([push])              # Whether push parsing is supported.
+b4_define_flag_if([push])              # Whether push parsing is requested.
 b4_define_flag_if([yacc])              # Whether POSIX Yacc is emulated.
 
 
Index: data/c.m4
===================================================================
RCS file: /sources/bison/bison/data/c.m4,v
retrieving revision 1.67
diff -p -u -r1.67 c.m4
--- data/c.m4   8 Oct 2006 11:07:02 -0000       1.67
+++ data/c.m4   26 Dec 2006 23:47:57 -0000
@@ -46,6 +46,9 @@ m4_define([b4_identification],
 /* Push parsers.  */
 [#]define YYPUSH b4_push_flag
 
+/* Pull parsers.  */
+[#]define YYPULL b4_pull_flag
+
 /* Using locations.  */
 [#]define YYLSP_NEEDED b4_locations_flag
 ])
Index: data/push.c
===================================================================
RCS file: /sources/bison/bison/data/push.c,v
retrieving revision 1.26
diff -p -u -r1.26 push.c
--- data/push.c 26 Dec 2006 18:09:53 -0000      1.26
+++ data/push.c 26 Dec 2006 23:47:57 -0000
@@ -63,32 +63,6 @@ b4_locations_if([, [[YYLTYPE *], [&yyllo
 m4_ifdef([b4_lex_param], b4_lex_param)))
 
 
-# b4_generate_macro_args([A], [B], [C], ...)
-# ---------------------------------------------------
-# Generate a comma-delimited list whose size is equal to the number of input
-# arguments and whose form is:
-#
-#   YYARG1, YYARG2, YYARG3, ...
-#
-# No argument should be the empty string except A in the special invocation
-# b4_generate_macro_args(), which generates an empty string.
-m4_define([b4_generate_macro_args],
-[m4_if([$1], [], [], [$#], [1], [[YYARG1]],
-       [b4_generate_macro_args(m4_shift($@)), [YYARG$#]])])
-
-
-# b4_parenthesize([A], [B], [C], ...)
-# ---------------------------------------------------
-# Convert arguments to the form:
-#
-#   (A), (B), (C), ...
-#
-# No argument should be the empty string except A in the special invocation
-# b4_parenthesize(), which generates an empty string.
-m4_define([b4_parenthesize],
-[m4_if([$1], [], [], [$#], [1], [[($1)]],
-       [($1), b4_parenthesize(m4_shift($@))])])
-
 ## ------------ ##
 ## Data Types.  ##
 ## ------------ ##
@@ -175,20 +149,20 @@ b4_copyright([Skeleton implementation fo
 
 ]b4_identification
 m4_if(b4_prefix, [yy], [],
-[/* Substitute the variable and function names.  */
-]b4_push_if([#define yypush_parse b4_prefix[]push_parse
-#define yypull_parse b4_prefix[]pull_parse
-#define yypstate_new b4_prefix[]pstate_new
-#define yypstate_delete b4_prefix[]pstate_delete
-#define yypstate b4_prefix[]pstate],
-[#define yyparse b4_prefix[]parse])[
-#define yylex   b4_prefix[]lex
-#define yyerror b4_prefix[]error
-#define yylval  b4_prefix[]lval
-#define yychar  b4_prefix[]char
-#define yydebug b4_prefix[]debug
-#define yynerrs b4_prefix[]nerrs
-b4_locations_if([#define yylloc b4_prefix[]lloc])])[
+[[/* Substitute the variable and function names.  */
+]b4_pull_if([[#define yyparse         ]b4_prefix[parse
+]])b4_push_if([[#define yypush_parse    ]b4_prefix[push_parse
+]b4_pull_if([[#define yypull_parse    ]b4_prefix[pull_parse
+]])[#define yypstate_new    ]b4_prefix[pstate_new
+#define yypstate_delete ]b4_prefix[pstate_delete
+#define yypstate        ]b4_prefix[pstate
+]])[#define yylex           ]b4_prefix[lex
+#define yyerror         ]b4_prefix[error
+#define yylval          ]b4_prefix[lval
+#define yychar          ]b4_prefix[char
+#define yydebug         ]b4_prefix[debug
+#define yynerrs         ]b4_prefix[nerrs
+]b4_locations_if([[#define yylloc          ]b4_prefix[lloc]])])[
 
 /* Copy the first part of user declarations.  */
 ]b4_user_pre_prologue[
@@ -248,20 +222,20 @@ b4_push_if([[#ifndef YYPUSH_DECLS
 struct yypstate;
 typedef struct yypstate yypstate;
 enum { YYPUSH_MORE = 4 };
-#  define yyparse(]b4_generate_macro_args(b4_parse_param))[ yypull_parse (0, 
&yylex]m4_ifset([b4_parse_param], [, 
b4_parenthesize(b4_generate_macro_args(b4_parse_param))])[)
-]b4_c_function_decl([[yypstate_new]], [[yypstate *]], [[[void]], []])
-b4_c_function_decl([[yypstate_delete]], [[void]],
-                   [[[yypstate *yyps]], [[yyps]]])
-b4_c_function_decl([[yypush_parse]], [[int]],
+
+]b4_pull_if([b4_c_function_decl([[yyparse]], [[int]], b4_parse_param)
+])b4_c_function_decl([[yypush_parse]], [[int]],
   [[[yypstate *yyps]], [[yyps]]]b4_pure_if([,
   [[[int yypushed_char]], [[yypushed_char]]],
   [[[YYSTYPE const *yypushed_val]], [[yypushed_val]]]b4_locations_if([,
   [[[YYLTYPE const *yypushed_loc]], 
[[yypushed_loc]]]])])m4_ifset([b4_parse_param], [,
   b4_parse_param]))
-b4_c_function_decl([[yypull_parse]], [[int]],
-  [[[yypstate *yyps]], [[yyps]]],
-  [[[int (*yylexp)(]b4_c_ansi_formals(b4_lex_param)[)]], 
[[yylexp]]]m4_ifset([b4_parse_param], [,
-  b4_parse_param]))[
+b4_pull_if([b4_c_function_decl([[yypull_parse]], [[int]],
+  [[[yypstate *yyps]], [[yyps]]]m4_ifset([b4_parse_param], [,
+  b4_parse_param]))])
+b4_c_function_decl([[yypstate_new]], [[yypstate *]], [[[void]], []])
+b4_c_function_decl([[yypstate_delete]], [[void]],
+                   [[[yypstate *yyps]], [[yyps]]])[
 #endif
 ]])
 m4_ifdef([b4_provides],
@@ -1087,9 +1061,14 @@ b4_push_if(
     int yynew;
   };
 
+]b4_pull_if([b4_c_function_def([[yyparse]], [[int]], b4_parse_param)[
+{
+  return yypull_parse (0]m4_ifset([b4_parse_param],
+                                  [[, ]b4_c_args(b4_parse_param)])[);
+}
+
 ]b4_c_function_def([[yypull_parse]], [[int]],
-  [[[yypstate *yyps]], [[yyps]]],
-  [[[int (*yylexp)(]b4_c_ansi_formals(b4_lex_param)[)]], 
[[yylexp]]]m4_ifset([b4_parse_param], [,
+  [[[yypstate *yyps]], [[yyps]]]m4_ifset([b4_parse_param], [,
   b4_parse_param]))[
 {
   int yystatus;
@@ -1103,7 +1082,7 @@ b4_push_if(
    else
      yyps_local = yyps;
    do {
-     yychar = ]b4_c_function_call([yylexp], [int], b4_lex_param)[;
+     yychar = YYLEX;
      yystatus =
        yypush_parse (yyps_local]b4_pure_if([[, yychar, 
&yylval]b4_locations_if([[, &yylloc]])])m4_ifset([b4_parse_param], [, 
b4_c_args(b4_parse_param)])[);
   } while (yystatus == YYPUSH_MORE);
@@ -1111,7 +1090,7 @@ b4_push_if(
     yypstate_delete (yyps_local);
   return yystatus;
 }
-
+]])[
 /* Initialize the parser data structure.  */
 ]b4_c_function_def([[yypstate_new]], [[yypstate *]])[
 {
@@ -1703,21 +1682,20 @@ b4_push_if([[#ifndef YYPUSH_DECLS
 struct ]b4_prefix[pstate;
 typedef struct ]b4_prefix[pstate ]b4_prefix[pstate;
 enum { YYPUSH_MORE = 4 };
-#  define ]b4_prefix[parse(]b4_generate_macro_args(b4_parse_param)) 
b4_prefix[pull_parse (0, &]b4_prefix[lex]m4_ifset([b4_parse_param], [, 
b4_parenthesize(b4_generate_macro_args(b4_parse_param))])[)
-]b4_c_function_decl([b4_prefix[pstate_new]], [b4_prefix[pstate *]],
-                    [[[void]], []])
-b4_c_function_decl([b4_prefix[pstate_delete]], [[void]],
-                   [[b4_prefix[pstate *yyps]], [[yyps]]])
-b4_c_function_decl([b4_prefix[push_parse]], [[int]],
+]b4_pull_if([b4_c_function_decl([b4_prefix[parse]], [[int]], b4_parse_param)
+])b4_c_function_decl([b4_prefix[push_parse]], [[int]],
   [[b4_prefix[pstate *yyps]], [[yyps]]]b4_pure_if([,
   [[[int yypushed_char]], [[yypushed_char]]],
   [[[YYSTYPE const *yypushed_val]], [[yypushed_val]]]b4_locations_if([,
   [[[YYLTYPE const *yypushed_loc]], 
[[yypushed_loc]]]])])m4_ifset([b4_parse_param], [,
   b4_parse_param]))
-b4_c_function_decl([b4_prefix[pull_parse]], [[int]],
-  [[b4_prefix[pstate *yyps]], [[yyps]]],
-  [[[int (*yylexp)(]b4_c_ansi_formals(b4_lex_param)[)]], 
[[yylexp]]]m4_ifset([b4_parse_param], [,
-  b4_parse_param]))[
+b4_pull_if([b4_c_function_decl([b4_prefix[pull_parse]], [[int]],
+  [[b4_prefix[pstate *yyps]], [[yyps]]]m4_ifset([b4_parse_param], [,
+  b4_parse_param]))])
+b4_c_function_decl([b4_prefix[pstate_new]], [b4_prefix[pstate *]],
+                    [[[void]], []])
+b4_c_function_decl([b4_prefix[pstate_delete]], [[void]],
+                   [[b4_prefix[pstate *yyps]], [[yyps]]])[
 #endif
 ]])
 m4_ifdef([b4_provides],
Index: etc/bench.pl.in
===================================================================
RCS file: /sources/bison/bison/etc/bench.pl.in,v
retrieving revision 1.1
diff -p -u -r1.1 bench.pl.in
--- etc/bench.pl.in     26 Dec 2006 18:09:53 -0000      1.1
+++ etc/bench.pl.in     26 Dec 2006 23:47:58 -0000
@@ -349,8 +349,8 @@ sub bench_grammar ($)
      "yacc.c-pull-pure" => '%pure-parser',
      "push.c-pull-impure" => '%skeleton "push.c"',
      "push.c-pull-pure" => '%skeleton "push.c" %pure-parser',
-     "push.c-push-impure" => '%skeleton "push.c" %push-parser',
-     "push.c-push-pure" => '%skeleton "push.c" %push-parser %pure-parser',
+     "push.c-push-impure" => '%skeleton "push.c" %push-pull-parser',
+     "push.c-push-pure" => '%skeleton "push.c" %push-pull-parser %pure-parser',
     );
   
   my %bench;
Index: src/getargs.c
===================================================================
RCS file: /sources/bison/bison/src/getargs.c,v
retrieving revision 1.87
diff -p -u -r1.87 getargs.c
--- src/getargs.c       19 Dec 2006 00:34:36 -0000      1.87
+++ src/getargs.c       26 Dec 2006 23:47:58 -0000
@@ -59,6 +59,7 @@ bool error_verbose = false;
 
 bool nondeterministic_parser = false;
 bool glr_parser = false;
+bool pull_parser = true;
 bool pure_parser = false;
 bool push_parser = false;
 
Index: src/getargs.h
===================================================================
RCS file: /sources/bison/bison/src/getargs.h,v
retrieving revision 1.37
diff -p -u -r1.37 getargs.h
--- src/getargs.h       19 Dec 2006 00:34:36 -0000      1.37
+++ src/getargs.h       26 Dec 2006 23:47:58 -0000
@@ -52,13 +52,16 @@ extern bool error_verbose;
 
 extern bool glr_parser;
 
+/* PULL_PARSER is true if should generate a pull parser.  */
+
+extern bool pull_parser;
+
 /* PURE_PARSER is true if should generate a parser that is all pure
    and reentrant.  */
 
 extern bool pure_parser;
 
-/* PUSH_PARSER is true if should generate a parser that is capable of being
-   called asynchronously.  Is must be pure and reentrant.  */
+/* PUSH_PARSER is true if should generate a push parser.  */
 
 extern bool push_parser;
 
Index: src/output.c
===================================================================
RCS file: /sources/bison/bison/src/output.c,v
retrieving revision 1.261
diff -p -u -r1.261 output.c
--- src/output.c        19 Dec 2006 00:34:36 -0000      1.261
+++ src/output.c        26 Dec 2006 23:47:58 -0000
@@ -593,6 +593,7 @@ prepare (void)
   MUSCLE_INSERT_BOOL ("glr_flag", glr_parser);
   MUSCLE_INSERT_BOOL ("locations_flag", locations_flag);
   MUSCLE_INSERT_BOOL ("nondeterministic_flag", nondeterministic_parser);
+  MUSCLE_INSERT_BOOL ("pull_flag", pull_parser);
   MUSCLE_INSERT_BOOL ("pure_flag", pure_parser);
   MUSCLE_INSERT_BOOL ("push_flag", push_parser);
   MUSCLE_INSERT_BOOL ("synclines_flag", !no_lines_flag);
Index: src/parse-gram.y
===================================================================
RCS file: /sources/bison/bison/src/parse-gram.y,v
retrieving revision 1.103
diff -p -u -r1.103 parse-gram.y
--- src/parse-gram.y    25 Dec 2006 17:25:39 -0000      1.103
+++ src/parse-gram.y    26 Dec 2006 23:47:59 -0000
@@ -156,6 +156,8 @@ static int current_prec = 0;
   PERCENT_PROVIDES        "%provides"
   PERCENT_PURE_PARSER     "%pure-parser"
   PERCENT_PUSH_PARSER     "%push-parser"
+  PERCENT_PUSH_PULL_PARSER
+                          "%push-pull-parser"
   PERCENT_REQUIRE        "%require"
   PERCENT_REQUIRES        "%requires"
   PERCENT_SKELETON        "%skeleton"
@@ -257,7 +259,8 @@ prologue_declaration:
 | "%output" "=" STRING          { spec_outfile = $3; }  /* deprecated */
 | "%parse-param" "{...}"       { add_param ("parse_param", $2, @2); }
 | "%pure-parser"                { pure_parser = true; }
-| "%push-parser"                { push_parser = true; }
+| "%push-parser"                { push_parser = true; pull_parser = false; }
+| "%push-pull-parser"           { push_parser = true; pull_parser = true; }
 | "%require" STRING             { version_check (&@2, $2); }
 | "%skeleton" STRING            { skeleton_arg ($2, 1, &@1); }
 | "%token-table"                { token_table_flag = true; }
Index: src/scan-gram.l
===================================================================
RCS file: /sources/bison/bison/src/scan-gram.l,v
retrieving revision 1.112
diff -p -u -r1.112 scan-gram.l
--- src/scan-gram.l     19 Dec 2006 00:34:36 -0000      1.112
+++ src/scan-gram.l     26 Dec 2006 23:47:59 -0000
@@ -189,7 +189,8 @@ splice       (\\[ \f\t\v]*\n)*
   "%printer"                       return PERCENT_PRINTER;
   "%provides"                       return PERCENT_PROVIDES;
   "%pure"[-_]"parser"              return PERCENT_PURE_PARSER;
-  "%push"[-_]"parser"              return PERCENT_PUSH_PARSER;
+  "%push-parser"                   return PERCENT_PUSH_PARSER;
+  "%push-pull-parser"              return PERCENT_PUSH_PULL_PARSER;
   "%require"                       return PERCENT_REQUIRE;
   "%requires"                       return PERCENT_REQUIRES;
   "%right"                         return PERCENT_RIGHT;
Index: tests/calc.at
===================================================================
RCS file: /sources/bison/bison/tests/calc.at,v
retrieving revision 1.101
diff -p -u -r1.101 calc.at
--- tests/calc.at       25 Dec 2006 18:21:52 -0000      1.101
+++ tests/calc.at       26 Dec 2006 23:47:59 -0000
@@ -562,7 +562,7 @@ AT_CHECK_CALC_LALR([%yacc])
 AT_CHECK_CALC_LALR([%error-verbose])
 
 AT_CHECK_CALC_LALR([%pure-parser %locations])
-AT_CHECK_CALC_LALR([%push-parser %pure-parser %locations %skeleton "push.c"])
+AT_CHECK_CALC_LALR([%push-pull-parser %pure-parser %locations %skeleton 
"push.c"])
 AT_CHECK_CALC_LALR([%error-verbose %locations])
 
 AT_CHECK_CALC_LALR([%error-verbose %locations %defines %name-prefix "calc" 
%verbose %yacc])
@@ -571,7 +571,7 @@ AT_CHECK_CALC_LALR([%debug])
 AT_CHECK_CALC_LALR([%error-verbose %debug %locations %defines %name-prefix 
"calc" %verbose %yacc])
 
 AT_CHECK_CALC_LALR([%pure-parser %error-verbose %debug %locations %defines 
%name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR([%push-parser %pure-parser %error-verbose %debug %locations 
%defines %name-prefix "calc" %verbose %yacc %skeleton "push.c"])
+AT_CHECK_CALC_LALR([%push-pull-parser %pure-parser %error-verbose %debug 
%locations %defines %name-prefix "calc" %verbose %yacc %skeleton "push.c"])
 
 AT_CHECK_CALC_LALR([%pure-parser %error-verbose %debug %locations %defines 
%name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} 
%parse-param {int *count}])
 
Index: tests/headers.at
===================================================================
RCS file: /sources/bison/bison/tests/headers.at,v
retrieving revision 1.16
diff -p -u -r1.16 headers.at
--- tests/headers.at    25 Dec 2006 18:21:52 -0000      1.16
+++ tests/headers.at    26 Dec 2006 23:47:59 -0000
@@ -94,9 +94,7 @@ AT_DATA_GRAMMAR([input.y],
 #include <stdio.h>
 #include <stdlib.h>
 
-int my_lex (void);
-
-int
+static int
 my_lex (void)
 {
   return EOF;
@@ -122,8 +120,6 @@ YYLTYPE *my_llocp = &my_lloc;
 
 #ifndef YYPUSH_DECLS
 int my_parse (void);
-#else
-int my_lex (void);
 #endif
 
 int
Index: tests/input.at
===================================================================
RCS file: /sources/bison/bison/tests/input.at,v
retrieving revision 1.65
diff -p -u -r1.65 input.at
--- tests/input.at      25 Dec 2006 18:21:52 -0000      1.65
+++ tests/input.at      26 Dec 2006 23:47:59 -0000
@@ -470,7 +470,7 @@ char quote[] = "@:>@@:>@,";
 
 %{
 static void yyerror (const char *s);
-int yylex (void);
+static int yylex (void);
 %}
 
 %type <ival> '@<:@'
@@ -503,7 +503,7 @@ value_as_yystype (value val)
   return res;
 }
 
-int
+static int
 yylex (void)
 {
   static char const input[] = 
"@<:@address@hidden@address@hidden@&address@hidden
@@ -531,8 +531,6 @@ AT_DATA([main.c],
 
 #ifndef YYPUSH_DECLS
 int yyparse (void);
-#else
-int yylex (void);
 #endif
 
 int
Index: tests/local.at
===================================================================
RCS file: /sources/bison/bison/tests/local.at,v
retrieving revision 1.21
diff -p -u -r1.21 local.at
--- tests/local.at      25 Dec 2006 17:25:39 -0000      1.21
+++ tests/local.at      26 Dec 2006 23:47:59 -0000
@@ -59,7 +59,7 @@ m4_pushdef([AT_LOCATION_IF],
 m4_pushdef([AT_PURE_IF],
 [m4_bmatch([$3], [%pure-parser], [$1], [$2])])
 m4_pushdef([AT_PUSH_IF],
-[m4_bmatch([$3], [%push-parser], [$1], [$2])])
+[m4_bmatch([$3], [%push-parser\|%push-pull-parser], [$1], [$2])])
 m4_pushdef([AT_YACC_OR_PUSH_IF],
 [AT_YACC_IF([$1], [AT_PUSH_IF([$1], [$2])])])
 m4_pushdef([AT_PURE_AND_LOC_IF],