Deprecate %pure-parser and add `%define api.pure'. Discussed starting

at
<http://lists.gnu.org/archive/html/bison-patches/2007-09/msg00006.html>.
* NEWS (2.3a+): Mention.
* data/bison.m4 (b4_pure_if): Don't define it here.
* data/c.m4 (b4_identification): Depend on individual skeletons to
define b4_pure_flag, b4_push_flag, or b4_pull_flag if they use the
values of the %define variables api.pure or api.push_pull.  Define
YYPURE, YYPUSH, and YYPULL accordingly.
* data/glr.c: Define b4_pure_if based on `%define api.pure' unless
glr.cc has already defined b4_pure_flag.
* data/push.c: Define b4_pure_if based on `%define api.pure'.
Remove YYPUSH and YYPULL since they're back in b4_identification again.
* data/yacc.c Define b4_pure_if based on `%define api.pure'.
* doc/bison.texinfo (Pure Decl): Update.
(Push Decl): Update.
(Decl Summary): Add api.pure to %define entry.
In %pure-parser entry, say it's deprecated and reference %define.
(Pure Calling): Update.
(Error Reporting): Update.
(C++ Scanner Interface): Update.
(How Can I Reset the Parser): Update.
(Table of Symbols): In %pure-parser entry, say it's deprecated and
reference %define.
* src/getargs.c (pure_parser): Remove global variable.
* src/getargs.h (pure_parser): Remove extern.
* src/output.c (prepare): Don't define pure_flag muscle.
* src/parse-gram.y (prologue_declaration): Implement %pure-parser as a
wrapper around `%define api.pure'.
* tests/calc.at (Simple LALR Calculator): Update.
(Simple GLR Calculator): Update.
* tests/cxx-type.at (GLR: Resolve ambiguity, pure, no locations):
Update.
(GLR: Resolve ambiguity, pure, locations): Update.
(GLR: Merge conflicting parses, pure, no locations): Update.
(GLR: Merge conflicting parses, pure, locations): Update.
* tests/glr-regression.at (Uninitialized location when reporting
ambiguity): Update
* tests/input.at (Unused %define api.pure): New test case.
* tests/local.at (_AT_BISON_OPTION_PUSHDEFS): Update definition for
AT_PURE_IF and AT_PURE_AND_LOC_IF.
* tests/push.at (Push Parsing: Memory Leak for Early Deletion): Update.

ChangeLog

@@ -1,3 +1,48 @@
+2007-10-28  Joel E. Denny  <jdenny@ces.clemson.edu>
+
+	Deprecate %pure-parser and add `%define api.pure'.  Discussed starting
+	at
+	<http://lists.gnu.org/archive/html/bison-patches/2007-09/msg00006.html>.
+	* NEWS (2.3a+): Mention.
+	* data/bison.m4 (b4_pure_if): Don't define it here.
+	* data/c.m4 (b4_identification): Depend on individual skeletons to
+	define b4_pure_flag, b4_push_flag, or b4_pull_flag if they use the
+	values of the %define variables api.pure or api.push_pull.  Define
+	YYPURE, YYPUSH, and YYPULL accordingly.
+	* data/glr.c: Define b4_pure_if based on `%define api.pure' unless
+	glr.cc has already defined b4_pure_flag.
+	* data/push.c: Define b4_pure_if based on `%define api.pure'.
+	Remove YYPUSH and YYPULL since they're back in b4_identification again.
+	* data/yacc.c Define b4_pure_if based on `%define api.pure'.
+	* doc/bison.texinfo (Pure Decl): Update.
+	(Push Decl): Update.
+	(Decl Summary): Add api.pure to %define entry.
+	In %pure-parser entry, say it's deprecated and reference %define.
+	(Pure Calling): Update.
+	(Error Reporting): Update.
+	(C++ Scanner Interface): Update.
+	(How Can I Reset the Parser): Update.
+	(Table of Symbols): In %pure-parser entry, say it's deprecated and
+	reference %define.
+	* src/getargs.c (pure_parser): Remove global variable.
+	* src/getargs.h (pure_parser): Remove extern.
+	* src/output.c (prepare): Don't define pure_flag muscle.
+	* src/parse-gram.y (prologue_declaration): Implement %pure-parser as a
+	wrapper around `%define api.pure'.
+	* tests/calc.at (Simple LALR Calculator): Update.
+	(Simple GLR Calculator): Update.
+	* tests/cxx-type.at (GLR: Resolve ambiguity, pure, no locations):
+	Update.
+	(GLR: Resolve ambiguity, pure, locations): Update.
+	(GLR: Merge conflicting parses, pure, no locations): Update.
+	(GLR: Merge conflicting parses, pure, locations): Update.
+	* tests/glr-regression.at (Uninitialized location when reporting
+	ambiguity): Update
+	* tests/input.at (Unused %define api.pure): New test case.
+	* tests/local.at (_AT_BISON_OPTION_PUSHDEFS): Update definition for
+	AT_PURE_IF and AT_PURE_AND_LOC_IF.
+	* tests/push.at (Push Parsing: Memory Leak for Early Deletion): Update.
+
 2007-10-28  Joel E. Denny  <jdenny@ces.clemson.edu>
 
 	%define push_pull -> %define api.push_pull.  Discussed starting at

NEWS

@@ -3,6 +3,18 @@ Bison News
 
 Changes in version 2.3a+ (????-??-??):
 
+* The quotes around NAME that used to be required in the following directive
+  are now deprecated:
+
+    %define NAME "VALUE"
+
+* The directive `%pure-parser' is now deprecated in favor of:
+
+    %define api.pure
+
+  which has the same effect except that Bison is more careful to warn about
+  unreasonable usage in the latter case.
+
 * Push Parsing
 
   Bison can now generate an LALR(1) parser in C with a push interface.  That
@@ -69,11 +81,6 @@ Changes in version 2.3a+ (????-??-??):
     %name-prefix "c_"
     %output "parser.c"
 
-* The quotes around NAME that used to be required in the following directive
-  are now deprecated:
-
-    %define NAME "VALUE"
-
 * An Alternative to `%{...%}' -- `%code QUALIFIER {CODE}'
 
   Bison 2.3a provided a new set of directives as a more flexible alternative to

data/bison.m4

@@ -249,7 +249,6 @@ b4_define_flag_if([error_verbose])	# Whether error are verbose.
 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([pure])	        # Whether the interface is pure.
 b4_define_flag_if([yacc])	        # Whether POSIX Yacc is emulated.
 
 

data/c.m4

@@ -28,22 +28,31 @@ m4_define([b4_comment], [/* m4_bpatsubst([$1], [
 
 # b4_identification
 # -----------------
+# Depends on individual skeletons to define b4_pure_flag, b4_push_flag, or
+# b4_pull_flag if they use the values of the %define variables api.pure or
+# api.push_pull.
 m4_define([b4_identification],
-[/* Identify Bison output.  */
+[[/* Identify Bison output.  */
-[#]define YYBISON 1
+#define YYBISON 1
 
 /* Bison version.  */
-[#]define YYBISON_VERSION "b4_version"
+#define YYBISON_VERSION "]b4_version["
 
 /* Skeleton name.  */
-[#]define YYSKELETON_NAME b4_skeleton
+#define YYSKELETON_NAME ]b4_skeleton[]m4_ifdef([b4_pure_flag], [[
 
 /* Pure parsers.  */
-[#]define YYPURE b4_pure_flag
+#define YYPURE ]b4_pure_flag])[]m4_ifdef([b4_push_flag], [[
+
+/* Push parsers.  */
+#define YYPUSH ]b4_push_flag])[]m4_ifdef([b4_pull_flag], [[
+
+/* Pull parsers.  */
+#define YYPULL ]b4_pull_flag])[
 
 /* Using locations.  */
-[#]define YYLSP_NEEDED b4_locations_flag
+#define YYLSP_NEEDED ]b4_locations_flag[
-])
+]])
 
 
 ## ---------------- ##

data/glr.c

@@ -34,6 +34,13 @@ m4_define_default([b4_stack_depth_init],  [200])
 ## Pure/impure interfaces.  ##
 ## ------------------------ ##
 
+b4_define_flag_if([pure])
+# If glr.cc is including this file and thus has already set b4_pure_flag, don't
+# change the value of b4_pure_flag, and don't record a use of api.pure.
+m4_ifndef([b4_pure_flag],
+[b4_percent_define_default([[api.pure]], [[false]])
+ m4_define([b4_pure_flag],
+           [b4_percent_define_flag_if([[api.pure]], [[1]], [[0]])])])
 
 # b4_user_formals
 # ---------------

data/push.c

@@ -51,6 +51,10 @@ m4_define_default([b4_stack_depth_init],  [200])
 ## Pure/impure interfaces.  ##
 ## ------------------------ ##
 
+b4_percent_define_default([[api.pure]], [[false]])
+b4_define_flag_if([pure])
+m4_define([b4_pure_flag],
+          [b4_percent_define_flag_if([[api.pure]], [[1]], [[0]])])
 
 # b4_yacc_pure_if(IF-TRUE, IF-FALSE)
 # ----------------------------------
@@ -163,14 +167,9 @@ b4_copyright([Skeleton implementation for Bison's Yacc-like parsers in C],dnl '
    define necessary library symbols; they are noted "INFRINGES ON
    USER NAME SPACE" below.  */
 
-]b4_identification[
+]b4_identification
-/* Push parsers.  */
-#define YYPUSH ]b4_push_flag[
 
-/* Pull parsers.  */
+b4_percent_code_get([[top]])[]dnl
-#define YYPULL ]b4_pull_flag[
-
-]b4_percent_code_get([[top]])[]dnl
 m4_if(b4_prefix, [yy], [],
 [[/* Substitute the variable and function names.  */
 ]b4_pull_if([[#define yyparse         ]b4_prefix[parse

data/yacc.c

@@ -37,6 +37,10 @@ m4_define_default([b4_stack_depth_init],  [200])
 ## Pure/impure interfaces.  ##
 ## ------------------------ ##
 
+b4_percent_define_default([[api.pure]], [[false]])
+b4_define_flag_if([pure])
+m4_define([b4_pure_flag],
+          [b4_percent_define_flag_if([[api.pure]], [[1]], [[0]])])
 
 # b4_yacc_pure_if(IF-TRUE, IF-FALSE)
 # ----------------------------------

doc/bison.texinfo

@@ -4487,7 +4487,7 @@ may override this restriction with the @code{%start} declaration as follows:
 @subsection A Pure (Reentrant) Parser
 @cindex reentrant parser
 @cindex pure parser
-@findex %pure-parser
+@findex %define api.pure
 
 A @dfn{reentrant} program is one which does not alter in the course of
 execution; in other words, it consists entirely of @dfn{pure} (read-only)
@@ -4503,11 +4503,11 @@ statically allocated variables for communication with @code{yylex},
 including @code{yylval} and @code{yylloc}.)
 
 Alternatively, you can generate a pure, reentrant parser.  The Bison
-declaration @code{%pure-parser} says that you want the parser to be
+declaration @code{%define api.pure} says that you want the parser to be
 reentrant.  It looks like this:
 
 @example
-%pure-parser
+%define api.pure
 @end example
 
 The result is that the communication variables @code{yylval} and
@@ -4554,7 +4554,7 @@ compatibility with the impure Yacc pull mode interface.  Unless you know
 what you are doing, your declarations should look like this:
 
 @example
-%pure-parser
+%define api.pure
 %define api.push_pull "push"
 @end example
 
@@ -4627,8 +4627,8 @@ yypull_parse (ps); /* Will call the lexer */
 yypstate_delete (ps);
 @end example
 
-Adding the @code{%pure-parser} declaration does exactly the same thing to the 
+Adding the @code{%define api.pure} declaration does exactly the same thing to
-generated parser with @code{%define api.push_pull "both"} as it did for 
+the generated parser with @code{%define api.push_pull "both"} as it did for 
 @code{%define api.push_pull "push"}.
 
 @node Decl Summary
@@ -4837,6 +4837,20 @@ target language and/or parser skeleton.
 Some of the accepted @var{variable}s are:
 
 @itemize @bullet
+@item api.pure
+@findex %define api.pure
+
+@itemize @bullet
+@item Language(s): C
+
+@item Purpose: Request a pure (reentrant) parser program.
+@xref{Pure Decl, ,A Pure (Reentrant) Parser}.
+
+@item Accepted Values: Boolean
+
+@item Default Value: @code{"false"}
+@end itemize
+
 @item api.push_pull
 @findex %define api.push_pull
 
@@ -5054,8 +5068,8 @@ Specify @var{file} for the parser file.
 @end deffn
 
 @deffn {Directive} %pure-parser
-Request a pure (reentrant) parser program (@pxref{Pure Decl, ,A Pure
+Deprecated version of @code{%define api.pure} (@pxref{Decl Summary, ,%define}),
-(Reentrant) Parser}).
+for which Bison is more careful to warn about unreasonable usage.
 @end deffn
 
 @deffn {Directive} %require "@var{version}"
@@ -5498,7 +5512,7 @@ The data type of @code{yylloc} has the name @code{YYLTYPE}.
 @node Pure Calling
 @subsection Calling Conventions for Pure Parsers
 
-When you use the Bison declaration @code{%pure-parser} to request a
+When you use the Bison declaration @code{%define api.pure} to request a
 pure, reentrant parser, the global communication variables @code{yylval}
 and @code{yylloc} cannot be used.  (@xref{Pure Decl, ,A Pure (Reentrant)
 Parser}.)  In such parsers the two global variables are replaced by
@@ -5549,7 +5563,7 @@ int yylex   (int *nastiness);
 int yyparse (int *nastiness, int *randomness);
 @end example
 
-If @code{%pure-parser} is added:
+If @code{%define api.pure} is added:
 
 @example
 int yylex   (YYSTYPE *lvalp, int *nastiness);
@@ -5557,7 +5571,7 @@ int yyparse (int *nastiness, int *randomness);
 @end example
 
 @noindent
-and finally, if both @code{%pure-parser} and @code{%locations} are used:
+and finally, if both @code{%define api.pure} and @code{%locations} are used:
 
 @example
 int yylex   (YYSTYPE *lvalp, YYLTYPE *llocp, int *nastiness);
@@ -5623,7 +5637,7 @@ Obviously, in location tracking pure parsers, @code{yyerror} should have
 an access to the current location.
 This is indeed the case for the @acronym{GLR}
 parsers, but not for the Yacc parser, for historical reasons.  I.e., if
-@samp{%locations %pure-parser} is passed then the prototypes for
+@samp{%locations %define api.pure} is passed then the prototypes for
 @code{yyerror} are:
 
 @example
@@ -5641,13 +5655,14 @@ void yyerror (int *nastiness, char const *msg);  /* GLR parsers.   */
 Finally, @acronym{GLR} and Yacc parsers share the same @code{yyerror} calling
 convention for absolutely pure parsers, i.e., when the calling
 convention of @code{yylex} @emph{and} the calling convention of
-@code{%pure-parser} are pure.  I.e.:
+@code{%define api.pure} are pure.
+I.e.:
 
 @example
 /* Location tracking.  */
 %locations
 /* Pure yylex.  */
-%pure-parser
+%define api.pure
 %lex-param   @{int *nastiness@}
 /* Pure yyparse.  */
 %parse-param @{int *nastiness@}
@@ -8108,7 +8123,7 @@ described by @var{m}.
 
 The parser invokes the scanner by calling @code{yylex}.  Contrary to C
 parsers, C++ parsers are always pure: there is no point in using the
-@code{%pure-parser} directive.  Therefore the interface is as follows.
+@code{%define api.pure} directive.  Therefore the interface is as follows.
 
 @deftypemethod {parser} {int} yylex (semantic_value_type& @var{yylval}, location_type& @var{yylloc}, @var{type1} @var{arg1}, ...)
 Return the next token.  Its type is the return value, its semantic
@@ -8860,10 +8875,9 @@ The return type can be changed using @samp{%define "stype"
 @end deftypemethod
 
 
-If @code{%pure-parser} is not specified, the lexer interface
+The lexer interface resides in the same class (@code{YYParser}) as the
-resides in the same class (@code{YYParser}) as the Bison-generated
+Bison-generated parser.
-parser. The fields and methods that are provided to
+The fields and methods that are provided to this end are as follows.
-this end are as follows.
 
 @deftypemethod {YYParser} {void} error (Location @var{l}, String @var{m})
 As explained in @pxref{Java Parser Interface}, this method is defined
@@ -8996,7 +9010,7 @@ or
 @display
 My parser includes support for an @samp{#include}-like feature, in
 which case I run @code{yyparse} from @code{yyparse}.  This fails
-although I did specify I needed a @code{%pure-parser}.
+although I did specify @code{%define api.pure}.
 @end display
 
 These problems typically come not from Bison itself, but from
@@ -9558,8 +9572,8 @@ Bison declaration to assign a precedence to a specific rule.
 @end deffn
 
 @deffn {Directive} %pure-parser
-Bison declaration to request a pure (reentrant) parser.
+Deprecated version of @code{%define api.pure} (@pxref{Decl Summary, ,%define}),
-@xref{Pure Decl, ,A Pure (Reentrant) Parser}.
+for which Bison is more careful to warn about unreasonable usage.
 @end deffn
 
 @deffn {Directive} %require "@var{version}"

src/getargs.c

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

src/getargs.h

@@ -51,11 +51,6 @@ extern bool error_verbose;
 
 extern bool glr_parser;
 
-/* PURE_PARSER is true if should generate a parser that is all pure
-   and reentrant.  */
-
-extern bool pure_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

@@ -571,7 +571,6 @@ 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 ("pure_flag", pure_parser);
   MUSCLE_INSERT_BOOL ("synclines_flag", !no_lines_flag);
   MUSCLE_INSERT_BOOL ("tag_seen_flag", tag_seen);
   MUSCLE_INSERT_BOOL ("use_push_for_pull_flag", use_push_for_pull_flag);

src/parse-gram.h

@@ -160,7 +160,7 @@
 typedef union YYSTYPE
 {
 
-/* Line 1538 of yacc.c  */
+/* Line 1542 of yacc.c  */
 #line 94 "parse-gram.y"
 
   symbol *symbol;
@@ -174,7 +174,7 @@ typedef union YYSTYPE
 
 
 
-/* Line 1538 of yacc.c  */
+/* Line 1542 of yacc.c  */
 #line 179 "parse-gram.h"
 } YYSTYPE;
 # define YYSTYPE_IS_TRIVIAL 1

src/parse-gram.y

@@ -266,7 +266,19 @@ prologue_declaration:
 | "%output" STRING              { spec_outfile = $2; }
 | "%output" "=" STRING          { spec_outfile = $3; }  /* deprecated */
 | "%parse-param" "{...}"	{ add_param ("parse_param", $2, @2); }
-| "%pure-parser"                { pure_parser = true; }
+| "%pure-parser"
+    {
+      /* %pure-parser is deprecated in favor of `%define api.pure', so use
+         `%define api.pure' in a backward-compatible manner here.  First, don't
+         complain if %pure-parser is specified multiple times.  */
+      if (!muscle_find_const ("percent_define(api.pure)"))
+        muscle_percent_define_insert ("api.pure", @1, "");
+      /* In all cases, use api.pure now so that the backend doesn't complain if
+         the skeleton ignores api.pure, but do warn now if there's a previous
+         conflicting definition from an actual %define.  */
+      if (!muscle_percent_define_flag_if ("api.pure"))
+        muscle_percent_define_insert ("api.pure", @1, "");
+    }
 | "%require" STRING             { version_check (&@2, $2); }
 | "%skeleton" STRING
     {

tests/calc.at

@@ -559,8 +559,8 @@ AT_CHECK_CALC_LALR([%verbose])
 AT_CHECK_CALC_LALR([%yacc])
 AT_CHECK_CALC_LALR([%error-verbose])
 
-AT_CHECK_CALC_LALR([%pure-parser %locations])
+AT_CHECK_CALC_LALR([%define api.pure %locations])
-AT_CHECK_CALC_LALR([%define api.push_pull "both" %pure-parser %locations])
+AT_CHECK_CALC_LALR([%define api.push_pull "both" %define api.pure %locations])
 AT_CHECK_CALC_LALR([%error-verbose %locations])
 
 AT_CHECK_CALC_LALR([%error-verbose %locations %defines %name-prefix "calc" %verbose %yacc])
@@ -568,10 +568,10 @@ AT_CHECK_CALC_LALR([%error-verbose %locations %defines %name-prefix "calc" %verb
 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([%define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
-AT_CHECK_CALC_LALR([%define api.push_pull "both" %pure-parser %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_LALR([%define api.push_pull "both" %define api.pure %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}])
+AT_CHECK_CALC_LALR([%define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
 
 
 # ----------------------- #
@@ -597,7 +597,7 @@ AT_CHECK_CALC_GLR([%verbose])
 AT_CHECK_CALC_GLR([%yacc])
 AT_CHECK_CALC_GLR([%error-verbose])
 
-AT_CHECK_CALC_GLR([%pure-parser %locations])
+AT_CHECK_CALC_GLR([%define api.pure %locations])
 AT_CHECK_CALC_GLR([%error-verbose %locations])
 
 AT_CHECK_CALC_GLR([%error-verbose %locations %defines %name-prefix "calc" %verbose %yacc])
@@ -605,9 +605,9 @@ AT_CHECK_CALC_GLR([%error-verbose %locations %defines %name-prefix "calc" %verbo
 AT_CHECK_CALC_GLR([%debug])
 AT_CHECK_CALC_GLR([%error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
 
-AT_CHECK_CALC_GLR([%pure-parser %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
+AT_CHECK_CALC_GLR([%define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc])
 
-AT_CHECK_CALC_GLR([%pure-parser %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
+AT_CHECK_CALC_GLR([%define api.pure %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
 
 
 # ----------------------------- #

tests/cxx-type.at

@@ -1,5 +1,6 @@
 # Checking GLR Parsing.                         -*- Autotest -*-
-# Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 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
@@ -423,14 +424,14 @@ AT_PARSER_CHECK([[./types test-input]], 0,
 AT_CLEANUP
 
 AT_SETUP([GLR: Resolve ambiguity, pure, no locations])
-_AT_TEST_GLR_CXXTYPES([%pure-parser],
+_AT_TEST_GLR_CXXTYPES([%define api.pure],
 		      [%dprec 1], [%dprec 2])
 AT_PARSER_CHECK([[./types test-input]], 0,
 		_AT_RESOLVED_GLR_OUTPUT, _AT_GLR_STDERR)
 AT_CLEANUP
 
 AT_SETUP([GLR: Resolve ambiguity, pure, locations])
-_AT_TEST_GLR_CXXTYPES([%pure-parser %locations],
+_AT_TEST_GLR_CXXTYPES([%define api.pure %locations],
 		      [%dprec 1], [%dprec 2])
 AT_PARSER_CHECK([[./types test-input]], 0,
 		_AT_RESOLVED_GLR_OUTPUT_WITH_LOC, _AT_GLR_STDERR)
@@ -451,13 +452,13 @@ AT_PARSER_CHECK([[./types test-input]], 0,
 AT_CLEANUP
 
 AT_SETUP([GLR: Merge conflicting parses, pure, no locations])
-_AT_TEST_GLR_CXXTYPES([%pure-parser],
+_AT_TEST_GLR_CXXTYPES([%define api.pure],
 		      [%merge <stmtMerge>], [%merge <stmtMerge>])
 AT_PARSER_CHECK([[./types test-input]], 0,
 		_AT_AMBIG_GLR_OUTPUT, _AT_GLR_STDERR)
 AT_CLEANUP
 AT_SETUP([GLR: Merge conflicting parses, pure, locations])
-_AT_TEST_GLR_CXXTYPES([%pure-parser %locations],
+_AT_TEST_GLR_CXXTYPES([%define api.pure %locations],
 		      [%merge <stmtMerge>],[%merge <stmtMerge>])
 AT_PARSER_CHECK([[./types test-input]], 0,
 		_AT_AMBIG_GLR_OUTPUT_WITH_LOC, _AT_GLR_STDERR)

tests/glr-regression.at

@@ -1646,7 +1646,7 @@ AT_DATA_GRAMMAR([glr-regr17.y],
 [[
 %glr-parser
 %locations
-%pure-parser
+%define api.pure
 %error-verbose
 
 %union { int dummy; }

tests/input.at

@@ -859,6 +859,39 @@ AT_CHECK([[bison input.y]], [1], [],
 
 AT_CLEANUP
 
+## ------------------------- ##
+## Unused %define api.pure.  ##
+## ------------------------- ##
+
+AT_SETUP([[Unused %define api.pure]])
+
+# AT_CHECK_API_PURE(DECLS, VALUE)
+# -------------------------------
+# Make sure Bison reports that `%define api.pure VALUE' is unused when DECLS
+# are specified.
+m4_define([AT_CHECK_API_PURE],
+[
+AT_DATA([[input.y]],
+[[%define api.pure ]$2[
+]$1[
+%%
+start: ;
+]])
+
+AT_CHECK([[bison input.y]], [0], [],
+[[input.y:1.9-16: warning: %define variable `api.pure' is not used
+]])
+])
+
+AT_CHECK_API_PURE([[%language "c++" %defines]], [[]])
+AT_CHECK_API_PURE([[%language "c++" %defines]], [["false"]])
+AT_CHECK_API_PURE([[%language "c++" %defines %glr-parser]], [[""]])
+AT_CHECK_API_PURE([[%language "c++" %defines %glr-parser]], [["false"]])
+AT_CHECK_API_PURE([[%language "java"]], [["true"]])
+AT_CHECK_API_PURE([[%language "java"]], [["false"]])
+
+AT_CLEANUP
+
 ## -------------------------------- ##
 ## C++ namespace reference errors.  ##
 ## -------------------------------- ##

tests/local.at

@@ -57,10 +57,11 @@ m4_pushdef([AT_PARAM_IF],
 m4_pushdef([AT_LOCATION_IF],
 [m4_bmatch([$3], [%locations], [$1], [$2])])
 m4_pushdef([AT_PURE_IF],
-[m4_bmatch([$3], [%pure-parser], [$1], [$2])])
+[m4_bmatch([$3], [%define  *api\.pure\|%pure-parser],
+           [m4_bmatch([$3], [%define  *api\.pure *"false"], [$2], [$1])],
+           [$2])])
 m4_pushdef([AT_PURE_AND_LOC_IF],
-[m4_bmatch([$3], [%locations.*%pure-parser\|%pure-parser.*%locations],
+[m4_bmatch([$3], [%locations], [AT_PURE_IF($@)], [$2])])
-	   [$1], [$2])])
 m4_pushdef([AT_GLR_OR_PARAM_IF],
 [m4_bmatch([$3], [%glr-parser\|%parse-param], [$1], [$2])])
 m4_pushdef([AT_NAME_PREFIX],
@@ -79,7 +80,7 @@ m4_pushdef([AT_YYERROR_SEES_LOC_IF],
 			    [$1])],
 		[$2])])
 
-# The interface is pure: either because %pure-parser, or because we
+# The interface is pure: either because %define api.pure, or because we
 # are using the C++ parsers.
 m4_pushdef([AT_PURE_LEX_IF],
 [AT_PURE_IF([$1],

tests/push.at

@@ -33,7 +33,7 @@ AT_DATA_GRAMMAR([[input.y]],
   void yyerror (char const *msg);
 %}
 
-%pure-parser %define api.push_pull "push"
+%define api.pure %define api.push_pull "push"
 
 %%