<http://lists.gnu.org/archive/html/bison-patches/2007-09/msg00005.html>.
* data/push.c: Expect the new name.
* data/yacc.c: Likewise.
* doc/bison.texinfo (Push Decl): Update.
(Decl Summary): Update %define entry.
(Push Parser Function): Update.
(Pull Parser Function): Update.
(Parser Create Function): Update.
(Parser Delete Function): Update.
* tests/calc.at (Simple LALR Calculator): Update.
* tests/input.at (%define enum variables): Update.
* tests/push.at (Push Parsing: Memory Leak for Early Deletion): Update.
(Push Parsing: Multiple impure instances): Update.
(Push Parsing: Unsupported Skeletons): Update.
* tests/torture.at (Exploding the Stack Size with Alloca): Update.
(Exploding the Stack Size with Malloc): Update.
* NEWS (2.3a+): Add an entry for the push parser, and clean up the
other entries some.
+2007-10-28 Joel E. Denny <jdenny@ces.clemson.edu>
+
+ %define push_pull -> %define api.push_pull. Discussed starting at
+ <http://lists.gnu.org/archive/html/bison-patches/2007-09/msg00005.html>.
+ * data/push.c: Expect the new name.
+ * data/yacc.c: Likewise.
+ * doc/bison.texinfo (Push Decl): Update.
+ (Decl Summary): Update %define entry.
+ (Push Parser Function): Update.
+ (Pull Parser Function): Update.
+ (Parser Create Function): Update.
+ (Parser Delete Function): Update.
+ * tests/calc.at (Simple LALR Calculator): Update.
+ * tests/input.at (%define enum variables): Update.
+ * tests/push.at (Push Parsing: Memory Leak for Early Deletion): Update.
+ (Push Parsing: Multiple impure instances): Update.
+ (Push Parsing: Unsupported Skeletons): Update.
+ * tests/torture.at (Exploding the Stack Size with Alloca): Update.
+ (Exploding the Stack Size with Malloc): Update.
+
+ * NEWS (2.3a+): Add an entry for the push parser, and clean up the
+ other entries some.
+
2007-10-27 Joel E. Denny <jdenny@ces.clemson.edu>
For the XML output's terminal element, rename @number to @token-number,
Changes in version 2.3a+ (????-??-??):
-* Previously, Bison sometimes generated parser tables containing unreachable
+* Push Parsing
+
+ Bison can now generate an LALR(1) parser in C with a push interface. That
+ is, instead of invoking yyparse, which pulls tokens from `yylex', you can
+ push one token at a time to the parser using `yypush_parse', which will
+ return to the caller after processing each token. By default, the push
+ interface is disabled. Either of the following directives will enable it:
+
+ %define api.push_pull "push" // Just push; does not require yylex.
+ %define api.push_pull "both" // Push and pull; requires yylex.
+
+ See the new section `A Push Parser' in the Bison manual for details.
+
+* The -g and --graph options now output graphs in Graphviz DOT format,
+ not VCG format.
+
+* An experimental directive %language specifies the language of the
+ generated parser, which can be C (the default) or C++. This
+ directive affects the skeleton used, and the names of the generated
+ files if the grammar file's name ends in ".y".
+
+* The grammar file may now specify the name of the parser header file using
+ %defines. For example:
+
+ %defines "parser.h"
+
+* Unreachable State Removal
+
+ Previously, Bison sometimes generated parser tables containing unreachable
states. A state can become unreachable during conflict resolution if Bison
disables a shift action leading to it from a predecessor state. Bison now:
See the %define entry in the `Bison Declaration Summary' in the Bison manual
for further discussion.
-* When instructed to generate a `.output' file including lookahead sets
+* Lookahead Set Correction in the `.output' Report
+
+ When instructed to generate a `.output' file including lookahead sets
(using `--report=lookahead', for example), Bison now prints each reduction's
lookahead set only next to the associated state's one item that (1) is
associated with the same rule as the reduction and (2) has its dot at the end
bug affected only the `.output' file and not the generated parser source
code.
-* The -g and --graph options now output graphs in Graphviz DOT format,
- not VCG format.
-
-* An experimental directive %language specifies the language of the
- generated parser, which can be C (the default) or C++. This
- directive affects the skeleton used, and the names of the generated
- files if the grammar file's name ends in ".y".
-
-* The grammar file may now specify the name of the parser header file using
- %defines. For example:
-
- %defines "parser.h"
-
* The `=' that used to be required in the following directives is now
deprecated:
%define NAME "VALUE"
-* Bison 2.3a provided a new set of directives as a more flexible alternative to
+* An Alternative to `%{...%}' -- `%code QUALIFIER {CODE}'
+
+ Bison 2.3a provided a new set of directives as a more flexible alternative to
the traditional Yacc prologue blocks. Those have now been consolidated into
a single %code directive with an optional qualifier field, which identifies
the purpose of the code and thus the location(s) where Bison should generate
To enable these warnings, specify the flag `--warnings=midrule-values' or
`-W', which is a synonym for `--warnings=all'.
-* Bison now recognizes two separate kinds of default %destructor's and
+* Default %destructor or %printer with `<*>' or `<>'
+
+ Bison now recognizes two separate kinds of default %destructor's and
%printer's:
1. Place `<*>' in a %destructor/%printer symbol list to define a default
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
-# Check the value of %define push_pull.
-b4_percent_define_default([[push_pull]], [[pull]])
-b4_percent_define_check_values([[[[push_pull]], [[pull]], [[push]], [[both]]]])
+# Check the value of %define api.push_pull.
+b4_percent_define_default([[api.push_pull]], [[pull]])
+b4_percent_define_check_values([[[[api.push_pull]],
+ [[pull]], [[push]], [[both]]]])
b4_define_flag_if([pull]) m4_define([b4_pull_flag], [[1]])
b4_define_flag_if([push]) m4_define([b4_push_flag], [[1]])
-m4_case(b4_percent_define_get([[push_pull]]),
+m4_case(b4_percent_define_get([[api.push_pull]]),
[pull], [m4_define([b4_push_flag], [[0]])],
[push], [m4_define([b4_pull_flag], [[0]])])
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# This hack will go away when we mv push.c yacc.c.
-m4_ifndef([b4_percent_define(push_pull)],
+m4_ifndef([b4_percent_define(api.push_pull)],
[m4_if(b4_use_push_for_pull_flag, [0], [
m4_include(b4_pkgdatadir/[c.m4])
@subsection A Push Parser
@cindex push parser
@cindex push parser
-@findex %define push_pull
+@findex %define api.push_pull
A pull parser is called once and it takes control until all its input
is completely parsed. A push parser, on the other hand, is called
Normally, Bison generates a pull parser.
The following Bison declaration says that you want the parser to be a push
-parser (@pxref{Decl Summary,,%define push_pull}):
+parser (@pxref{Decl Summary,,%define api.push_pull}):
@example
-%define push_pull "push"
+%define api.push_pull "push"
@end example
In almost all cases, you want to ensure that your push parser is also
@example
%pure-parser
-%define push_pull "push"
+%define api.push_pull "push"
@end example
There is a major notable functional difference between the pure push parser
Bison also supports both the push parser interface along with the pull parser
interface in the same generated parser. In order to get this functionality,
-you should replace the @code{%define push_pull "push"} declaration with the
-@code{%define push_pull "both"} declaration. Doing this will create all of the
-symbols mentioned earlier along with the two extra symbols, @code{yyparse}
+you should replace the @code{%define api.push_pull "push"} declaration with the
+@code{%define api.push_pull "both"} declaration. Doing this will create all of
+the symbols mentioned earlier along with the two extra symbols, @code{yyparse}
and @code{yypull_parse}. @code{yyparse} can be used exactly as it normally
would be used. However, the user should note that it is implemented in the
generated parser by calling @code{yypull_parse}.
This makes the @code{yyparse} function that is generated with the
-@code{%define push_pull "both"} declaration slower than the normal
+@code{%define api.push_pull "both"} declaration slower than the normal
@code{yyparse} function. If the user
calls the @code{yypull_parse} function it will parse the rest of the input
stream. It is possible to @code{yypush_parse} tokens to select a subgrammar
@end example
Adding the @code{%pure-parser} declaration does exactly the same thing to the
-generated parser with @code{%define push_pull "both"} as it did for
-@code{%define push_pull "push"}.
+generated parser with @code{%define api.push_pull "both"} as it did for
+@code{%define api.push_pull "push"}.
@node Decl Summary
@subsection Bison Declaration Summary
Some of the accepted @var{variable}s are:
@itemize @bullet
-@item push_pull
-@findex %define push_pull
+@item api.push_pull
+@findex %define api.push_pull
@itemize @bullet
@item Language(s): C (LALR(1) only)
@findex yypush_parse
You call the function @code{yypush_parse} to parse a single token. This
-function is available if either the @code{%define push_pull "push"} or
-@code{%define push_pull "both"} declaration is used.
+function is available if either the @code{%define api.push_pull "push"} or
+@code{%define api.push_pull "both"} declaration is used.
@xref{Push Decl, ,A Push Parser}.
@deftypefun int yypush_parse (yypstate *yyps)
@findex yypull_parse
You call the function @code{yypull_parse} to parse the rest of the input
-stream. This function is available if the @code{%define push_pull "both"}
+stream. This function is available if the @code{%define api.push_pull "both"}
declaration is used.
@xref{Push Decl, ,A Push Parser}.
@findex yypstate_new
You call the function @code{yypstate_new} to create a new parser instance.
-This function is available if either the @code{%define push_pull "push"} or
-@code{%define push_pull "both"} declaration is used.
+This function is available if either the @code{%define api.push_pull "push"} or
+@code{%define api.push_pull "both"} declaration is used.
@xref{Push Decl, ,A Push Parser}.
@deftypefun yypstate *yypstate_new (void)
@findex yypstate_delete
You call the function @code{yypstate_delete} to delete a parser instance.
-function is available if either the @code{%define push_pull "push"} or
-@code{%define push_pull "both"} declaration is used.
+function is available if either the @code{%define api.push_pull "push"} or
+@code{%define api.push_pull "both"} declaration is used.
@xref{Push Decl, ,A Push Parser}.
@deftypefun void yypstate_delete (yypstate *yyps)
AT_CHECK_CALC_LALR([%error-verbose])
AT_CHECK_CALC_LALR([%pure-parser %locations])
-AT_CHECK_CALC_LALR([%define push_pull "both" %pure-parser %locations])
+AT_CHECK_CALC_LALR([%define api.push_pull "both" %pure-parser %locations])
AT_CHECK_CALC_LALR([%error-verbose %locations])
AT_CHECK_CALC_LALR([%error-verbose %locations %defines %name-prefix "calc" %verbose %yacc])
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 push_pull "both" %pure-parser %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([%pure-parser %error-verbose %debug %locations %defines %name-prefix "calc" %verbose %yacc %parse-param {semantic_value *result} %parse-param {int *count}])
AT_SETUP([[%define enum variables]])
AT_DATA([[input.y]],
-[[%define push_pull "neither"
+[[%define api.push_pull "neither"
%%
start: ;
]])
AT_CHECK([[bison input.y]], [1], [],
-[[input.y:1.9-17: invalid value for %define variable `push_pull': `neither'
+[[input.y:1.9-21: invalid value for %define variable `api.push_pull': `neither'
]])
AT_CLEANUP
void yyerror (char const *msg);
%}
-%pure-parser %define push_pull "push"
+%pure-parser %define api.push_pull "push"
%%
int yylex (void);
%}
-%define push_pull "both"
+%define api.push_pull "both"
%%
AT_DATA([[input.y]],
[[%glr-parser
-%define push_pull "push"
+%define api.push_pull "push"
%%
start: ;
]])
AT_CHECK([[bison input.y]], [0], [],
-[[input.y:2.9-17: warning: %define variable `push_pull' is not used
+[[input.y:2.9-21: warning: %define variable `api.push_pull' is not used
]])
AT_CLEANUP
# just helps guarantee we don't let the YYSTACK_USE_ALLOCA feature affect
# push parsers.
AT_DATA_STACK_TORTURE([AT_USE_ALLOCA],
-[[%define push_pull "both"
+[[%define api.push_pull "both"
]])
AT_PARSER_CHECK([./input 20], 0, [], [ignore],
[[VALGRIND_OPTS="$VALGRIND_OPTS --log-fd=1"]])
[[VALGRIND_OPTS="$VALGRIND_OPTS --log-fd=1"]])
AT_DATA_STACK_TORTURE([AT_USE_ALLOCA],
-[[%define push_pull "both"
+[[%define api.push_pull "both"
]])
AT_PARSER_CHECK([./input 20], 0, [], [ignore],
[[VALGRIND_OPTS="$VALGRIND_OPTS --log-fd=1"]])
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