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* data/c.m4 (b4_yydestruct_generate, b4_yysymprint_generate): Pass

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the %parse-params.
* data/glr.c (YY_SYMBOL_PRINT, yydestroyGLRState): Adjust.
* data/yacc.c (b4_Pure_if): Rename as...
(b4_yacc_pure_if): this.
(YY_SYMBOL_PRINT, yyparse): Adjust.
* doc/bison.texinfo: Formatting changes.
This commit is contained in:
Akim Demaille
2005-10-21 11:36:22 +00:00
parent 24cc23d96d
commit 4b3673159e
8 changed files with 205 additions and 186 deletions
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doc/bison.texinfo
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@@ -3810,28 +3810,28 @@ For instance, if your locations use a file name, you may use
@cindex freeing discarded symbols
@findex %destructor
Some symbols can be discarded by the parser. During error
recovery (@pxref{Error Recovery}), symbols already pushed
on the stack and tokens coming from the rest of the file
are discarded until the parser falls on its feet. If the parser
runs out of memory, all the symbols on the stack must be discarded.
Even if the parser succeeds, it must discard the start symbol.
Some symbols can be discarded by the parser. During error recovery
(@pxref{Error Recovery}), symbols already pushed on the stack and tokens
coming from the rest of the file are discarded until the parser falls on
its feet. If the parser runs out of memory, all the symbols on the
stack must be discarded. Even if the parser succeeds, it must discard
the start symbol.
When discarded symbols convey heap based information, this memory is
lost. While this behavior can be tolerable for batch parsers, such as
in traditional compilers, it is unacceptable for programs like shells
or protocol implementations that may parse and execute indefinitely.
in traditional compilers, it is unacceptable for programs like shells or
protocol implementations that may parse and execute indefinitely.
The @code{%destructor} directive defines code that
is called when a symbol is discarded.
@deffn {Directive} %destructor @{ @var{code} @} @var{symbols}
@findex %destructor
Invoke @var{code} whenever the parser discards one of the
@var{symbols}. Within @var{code}, @code{$$} designates the semantic
value associated with the discarded symbol. The additional
parser parameters are also available
(@pxref{Parser Function, , The Parser Function @code{yyparse}}).
Invoke @var{code} whenever the parser discards one of the @var{symbols}.
Within @var{code}, @code{$$} designates the semantic value associated
with the discarded symbol. The additional parser parameters are also
available (@pxref{Parser Function, , The Parser Function
@code{yyparse}}).
@strong{Warning:} as of Bison 2.1, this feature is still
experimental, as there has not been enough user feedback. In particular,