* 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.

ChangeLog

@@ -1,3 +1,18 @@
+2006-09-15  Bob Rossi  <bob@brasko.net>
+
+	* 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.
+
 2006-09-13  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* NEWS: Version 2.3a.

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.  ##

src/getargs.c

@@ -59,6 +59,7 @@ bool error_verbose = false;
 bool nondeterministic_parser = false;
 bool glr_parser = false;
 bool pure_parser = false;
+bool push_parser = false;
 
 int report_flag = report_none;
 int trace_flag = trace_none;

src/getargs.h

@@ -53,6 +53,11 @@ extern bool glr_parser;
 
 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.  */
+
+extern bool push_parser;
+
 /* NONDETERMINISTIC_PARSER is true iff conflicts are accepted.  This
    is used by the GLR parser, and might be used in BackTracking
    parsers too.  */

src/output.c

@@ -585,6 +585,7 @@ prepare (void)
   MUSCLE_INSERT_BOOL ("error_verbose_flag", error_verbose);
   MUSCLE_INSERT_BOOL ("locations_flag", locations_flag);
   MUSCLE_INSERT_BOOL ("pure_flag", pure_parser);
+  MUSCLE_INSERT_BOOL ("push_flag", push_parser);
   MUSCLE_INSERT_BOOL ("synclines_flag", !no_lines_flag);
   MUSCLE_INSERT_BOOL ("tag_seen_flag", tag_seen);
   MUSCLE_INSERT_BOOL ("yacc_flag", yacc_flag);

src/parse-gram.y

@@ -156,6 +156,7 @@ static int current_prec = 0;
   PERCENT_OUTPUT          "%output"
   PERCENT_PARSE_PARAM     "%parse-param"
   PERCENT_PURE_PARSER     "%pure-parser"
+  PERCENT_PUSH_PARSER     "%push-parser"
   PERCENT_REQUIRE	  "%require"
   PERCENT_SKELETON        "%skeleton"
   PERCENT_START           "%start"
@@ -248,6 +249,7 @@ prologue_declaration:
 | "%output" "=" STRING          { spec_outfile = $3; }
 | "%parse-param" "{...}"	{ add_param ("parse_param", $2, @2); }
 | "%pure-parser"                { pure_parser = true; }
+| "%push-parser"                { push_parser = true; }
 | "%require" STRING             { version_check (&@2, $2); }
 | "%skeleton" STRING            { skeleton = $2; }
 | "%start-header" braceless     { muscle_code_grow ("start_header", $2, @2); }

src/scan-gram.l

@@ -188,6 +188,7 @@ splice	 (\\[ \f\t\v]*\n)*
   "%prec"                 	    return PERCENT_PREC;
   "%printer"              	    return PERCENT_PRINTER;
   "%pure"[-_]"parser"     	    return PERCENT_PURE_PARSER;
+  "%push"[-_]"parser"		    return PERCENT_PUSH_PARSER;
   "%require"              	    return PERCENT_REQUIRE;
   "%right"                	    return PERCENT_RIGHT;
   "%skeleton"             	    return PERCENT_SKELETON;

tests/calc.at

@@ -412,11 +412,13 @@ sed '/^Starting/d
 /^Stack/d
 /^Reading/d
 /^Reducing/d
+/^Return/d
 /^Shifting/d
 /^state/d
 /^Cleanup:/d
 /^Error:/d
 /^Next/d
+/^Now/d
 /^Discarding/d
 / \$[[0-9$]]* = /d
 /^yydestructor:/d' stderr >at-stderr
@@ -559,6 +561,7 @@ AT_CHECK_CALC_LALR([%yacc])
 AT_CHECK_CALC_LALR([%error-verbose])
 
 AT_CHECK_CALC_LALR([%pure-parser %locations])
+AT_CHECK_CALC_LALR([%push-parser %locations])
 AT_CHECK_CALC_LALR([%error-verbose %locations])
 
 AT_CHECK_CALC_LALR([%error-verbose %locations %defines %name-prefix="calc" %verbose %yacc])
@@ -567,6 +570,7 @@ 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 %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 %parse-param {semantic_value *result} %parse-param {int *count}])