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Replace %push-parser' and %push-pull-parser' with

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`%define push_pull "push"' and `%define push_pull "both"'.
`%define push_pull "pull"' is the default.
* doc/bison.texinfo (Push Decl, Push Parser Function,
Pull Parser Function, Parser Create Function, Parser Delete Function):
Update declarations.
(Decl Summary, Table of Symbols): Replace %push-parser and
%push-pull-parser entries with a %define push_pull entry.
* data/bison.m4 (b4_percent_define_check_values): New macro.
(b4_pull_if, b4_push_if, b4_use_push_for_pull_if): Move these
definitions...
* data/c.m4 (b4_identification): ... and the YYPUSH and YYPULL cpp
definitions...
* data/push.c: ... to here and compute them from the value of the
%define variable push_pull.
* data/c-skel.m4: Instead of choosing the push.c skeleton for push
parsing requests here...
* data/yacc.c: ... hack this to switch to push.c any time
b4_use_push_pull_flag or the %define variable push_pull is set.  This
will go away when we mv push.c yacc.c.
* data/c++-skel.m4, data/glr.c, data/java-skel.m4: Don't report that
push parsing is not supported since unused %define variables are
reported anyway.
* src/getargs.c, src/getargs.h (pull_parser, push_parser): Remove.
* src/muscle_tab.h (muscle_percent_define_check_values): Update
comments for consistency with b4_percent_define_check_values.
* src/output.c (prepare): Don't insert b4_pull_flag and b4_push_flag
muscles.
* src/parse-gram.y (PERCENT_PUSH_PARSER, PERCENT_PUSH_PULL_PARSER):
Remove.
(prologue_declaration): Remove %push-parser and %push-pull-parser
rules.
* src/scan-gram.l (%push-parser, %push-pull-parser): Remove rules.
* tests/calc.at: Update declarations.
* tests/input.at (%define enum variables): New test case.
* tests/push.at (Push Parsing: Memory Leak for Early Deletion): Update
declaration.
(Push Parsing: Multiple impure instances): Update declaration.
(Push Parsing: Unsupported Skeletons): New test case.
* tests/torture.at (Exploding the Stack Size with Alloca): Update
declaration.
(Exploding the Stack Size with Malloc): Update declaration.
This commit is contained in:
Joel E. Denny
2007-09-25 05:47:27 +00:00
parent 3f999f78be
commit d782395d52
22 changed files with 771 additions and 713 deletions
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77
doc/bison.texinfo
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@@ -4528,7 +4528,7 @@ valid grammar.
@subsection A Push Parser
@cindex push parser
@cindex push parser
@findex %push-parser
@findex %define 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
@@ -4539,12 +4539,12 @@ main event loop in the client's application. This is typically
a requirement of a GUI, when the main event loop needs to be triggered
within a certain time period.
Normally, Bison generates a pull parser. The Bison declaration
@code{%push-parser} says that you want the parser to be a push parser.
It looks like this:
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}):
@example
%push-parser
%define push_pull "push"
@end example
In almost all cases, you want to ensure that your push parser is also
@@ -4555,7 +4555,7 @@ what you are doing, your declarations should look like this:
@example
%pure-parser
%push-parser
%define push_pull "push"
@end example
There is a major notable functional difference between the pure push parser
@@ -4604,15 +4604,16 @@ for use by the next invocation of the @code{yypush_parse} function.
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{%push-parser} declaration with the
@code{%push-pull-parser} declaration. Doing this will create all of the
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}
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{%push-pull-parser}
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
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{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
and then @code{yypull_parse} the rest of the input stream. If you would like
to switch back and forth between between parsing styles, you would have to
@@ -4627,8 +4628,8 @@ yypstate_delete (ps);
@end example
Adding the @code{%pure-parser} declaration does exactly the same thing to the
generated parser with @code{%push-pull-parser} as it did for
@code{%push-parser}.
generated parser with @code{%define push_pull "both"} as it did for
@code{%define push_pull "push"}.
@node Decl Summary
@subsection Bison Declaration Summary
@@ -4834,6 +4835,14 @@ target language and/or parser skeleton.
@end enumerate
@end deffn
@deffn {Directive} %define push_pull "@var{value}"
Bison declaration to request a @code{"pull"} parser, a @code{"push"} parser, or
@code{"both"}.
The default @code{"@var{value}"} is @code{"pull"}.
This directive is currently only available for LALR(1) parsers in C.
@xref{Push Decl, ,A Push Parser}.
@end deffn
@deffn {Directive} %defines
Write a header file containing macro definitions for the token type
names defined in the grammar as well as a few other declarations.
@@ -4944,16 +4953,6 @@ Request a pure (reentrant) parser program (@pxref{Pure Decl, ,A Pure
(Reentrant) Parser}).
@end deffn
@deffn {Directive} %push-parser
Bison declaration to request a push parser.
@xref{Push Decl, ,A Push Parser}.
@end deffn
@deffn {Directive} %push-pull-parser
Bison declaration to request a push and a pull parser.
@xref{Push Decl, ,A Push Parser}.
@end deffn
@deffn {Directive} %require "@var{version}"
Require version @var{version} or higher of Bison. @xref{Require Decl, ,
Require a Version of Bison}.
@@ -5163,8 +5162,8 @@ exp: @dots{} @{ @dots{}; *randomness += 1; @dots{} @}
@findex yypush_parse
You call the function @code{yypush_parse} to parse a single token. This
function is available if either the @code{%push-parser} or
@code{%push-pull-parser} declaration is used.
function is available if either the @code{%define push_pull "push"} or
@code{%define push_pull "both"} declaration is used.
@xref{Push Decl, ,A Push Parser}.
@deftypefun int yypush_parse (yypstate *yyps)
@@ -5178,7 +5177,7 @@ is required to finish parsing the grammar.
@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{%push-pull-parser}
stream. This function is available if the @code{%define push_pull "both"}
declaration is used.
@xref{Push Decl, ,A Push Parser}.
@@ -5191,8 +5190,8 @@ The value returned by @code{yypull_parse} is the same as for @code{yyparse}.
@findex yypstate_new
You call the function @code{yypstate_new} to create a new parser instance.
This function is available if either the @code{%push-parser} or
@code{%push-pull-parser} declaration is used.
This function is available if either the @code{%define push_pull "push"} or
@code{%define push_pull "both"} declaration is used.
@xref{Push Decl, ,A Push Parser}.
@deftypefun yypstate *yypstate_new (void)
@@ -5205,8 +5204,8 @@ or NULL if no memory was available.
@findex yypstate_delete
You call the function @code{yypstate_delete} to delete a parser instance.
This function is available if either the @code{%push-parser} or
@code{%push-pull-parser} declaration is used.
function is available if either the @code{%define push_pull "push"} or
@code{%define push_pull "both"} declaration is used.
@xref{Push Decl, ,A Push Parser}.
@deftypefun void yypstate_delete (yypstate *yyps)
@@ -9330,6 +9329,12 @@ Define a variable to adjust Bison's behavior.
@xref{Decl Summary,,%define}.
@end deffn
@deffn {Directive} %define push_pull "@var{value}"
Bison declaration to request a @code{"pull"} parser, a @code{"push"} parser, or
@code{"both"}.
@xref{Decl Summary,,%define push_pull}.
@end deffn
@deffn {Directive} %defines
Bison declaration to create a header file meant for the scanner.
@xref{Decl Summary}.
@@ -9452,16 +9457,6 @@ Bison declaration to request a pure (reentrant) parser.
@xref{Pure Decl, ,A Pure (Reentrant) Parser}.
@end deffn
@deffn {Directive} %push-parser
Bison declaration to request a push parser.
@xref{Push Decl, ,A Push Parser}.
@end deffn
@deffn {Directive} %push-pull-parser
Bison declaration to request a push and a pull parser.
@xref{Push Decl, ,A Push Parser}.
@end deffn
@deffn {Directive} %require "@var{version}"
Require version @var{version} or higher of Bison. @xref{Require Decl, ,
Require a Version of Bison}.