* data/Makefile.am (dist_pkgdata_DATA): Add push.c.

* data/c.m4 (YYPUSH): New.
(b4_push_if): New macro.  Use it instead of #ifdef YYPUSH.
* src/getargs.c (push_parser): New var.
* src/getargs.h (push_parser): New declaration.
* src/output.c (prepare): Add macro insertion of `push_flag'.
* src/parse-gram.y (PERCENT_PUSH_PARSER): New token.
(prologue_declaration): Parse %push-parser.
* src/scan-gram.l: Scan new PERCENT_PUSH_PARSER token.
* tests/calc.at (_AT_CHECK_CALC_ERROR): Add "Return" and "Now" to
list of removed lines from the traces observed.
(AT_CHECK_CALC_LALR): Added push parser tests.

data/Makefile.am

@@ -1,4 +1,4 @@
-## Copyright (C) 2002, 2005 Free Software Foundation, Inc.
+## Copyright (C) 2002, 2005, 2006 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
@@ -16,7 +16,7 @@
 ## 02110-1301  USA
 
 dist_pkgdata_DATA = README \
-   c.m4 yacc.c glr.c \
+   c.m4 yacc.c glr.c push.c \
    c++.m4 location.cc lalr1.cc glr.cc
 
 m4sugardir = $(pkgdatadir)/m4sugar

data/c.m4

@@ -76,6 +76,9 @@ m4_define([b4_identification],
 /* Pure parsers.  */
 [#]define YYPURE b4_pure_flag
 
+/* Push parsers.  */
+[#]define YYPUSH b4_push_flag
+
 /* Using locations.  */
 [#]define YYLSP_NEEDED b4_locations_flag
 ])
@@ -225,6 +228,15 @@ b4_define_flag_if([pure])           # Whether the interface is pure.
 b4_define_flag_if([yacc])           # Whether POSIX Yacc is emulated.
 
 
+# b4_push_if(IF-TRUE, IF-FALSE)
+# -----------------------------
+# Expand IF-TRUE, if %push-parser, IF-FALSE otherwise.
+m4_define([b4_push_if],
+[m4_if(b4_push_flag, [1],
+       [$1],
+       [$2])])
+
+
 
 ## ------------------------- ##
 ## Assigning token numbers.  ##