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* NEWS: Reword %destructor vs YYABORT etc.

Browse Source 
* data/glr.c: Use American spacing, for consistency.
* data/glr.cc: Likewise.
* data/lalr1.cc: Likewise.
* data/yacc.c: Likewise.
* data/yacc.c: Reformat comments slightly.
* doc/bison.texinfo: Replace "non-" with "non" when that makes sense,
for consistency.  Fix some spelling errors and reword recently-included
text slightly.
* tests/cxx-type.at: Cast results of malloc, for C++.
This commit is contained in:
Paul Eggert
2005-12-22 00:24:40 +00:00
parent 2c3b392a9a
commit 9d9b8b7006
8 changed files with 138 additions and 124 deletions
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13
ChangeLog
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@@ -1,3 +1,16 @@
2005-12-21 Paul Eggert <eggert@cs.ucla.edu>
* NEWS: Reword %destructor vs YYABORT etc.
* data/glr.c: Use American spacing, for consistency.
* data/glr.cc: Likewise.
* data/lalr1.cc: Likewise.
* data/yacc.c: Likewise.
* data/yacc.c: Reformat comments slightly.
* doc/bison.texinfo: Replace "non-" with "non" when that makes sense,
for consistency. Fix some spelling errors and reword recently-included
text slightly.
* tests/cxx-type.at: Cast results of malloc, for C++.
2005-12-21 Joel E. Denny <address@hidden>
* tests/cxx-type.at: Construct a tree, count the parents of shared

8
NEWS
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@@ -3,10 +3,10 @@ Bison News
Changes in version 2.1a:
* %destructor vs. YYACCEPT, YYERROR, and YYABORT.
When the parsing/action is cut by the user using one of these
special actions, the stack is freed except the right-hand side
symbols of the current rule.
* %destructor vs. YYABORT, YYACCEPT, and YYERROR.
Destructors are now called when user code invokes YYABORT, YYACCEPT,
and YYERROR, for all objects on the stack, other than objects
corresponding to the right-hand side of the current rule.
* GLR, C++ LALR(1) parsers.
These parser skeletons are now distributed with the same special

7
data/yacc.c
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@@ -666,7 +666,7 @@ do { \
[[short int *top], [top]])[
{
YYFPRINTF (stderr, "Stack now");
for (/* Nothing. */; bottom <= top; ++bottom)
for (; bottom <= top; ++bottom)
YYFPRINTF (stderr, " %d", *bottom);
YYFPRINTF (stderr, "\n");
}
@@ -1052,7 +1052,7 @@ b4_c_function_def([yyparse], [int], b4_parse_param)
]b4_location_if([ YYLTYPE yyloc;])[
/* The number of symbols on the RHS of the reduced rule.
Keep to zero when no symbol should be popped off. */
Keep to zero when no symbol should be popped. */
int yylen = 0;
YYDPRINTF ((stderr, "Starting parse\n"));
@@ -1097,8 +1097,7 @@ m4_ifdef([b4_at_dollar_used], [[ yylsp[0] = yylloc;
`------------------------------------------------------------*/
yynewstate:
/* In all cases, when you get here, the value and location stacks
have just been pushed. so pushing a state here evens the stacks.
*/
have just been pushed. So pushing a state here evens the stacks. */
yyssp++;
yysetstate:

50
doc/bison.texinfo
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@@ -461,7 +461,7 @@ more information on this.
@cindex @acronym{GLR} parsing
@cindex generalized @acronym{LR} (@acronym{GLR}) parsing
@cindex ambiguous grammars
@cindex non-deterministic parsing
@cindex nondeterministic parsing
Parsers for @acronym{LALR}(1) grammars are @dfn{deterministic}, meaning
roughly that the next grammar rule to apply at any point in the input is
@@ -469,7 +469,7 @@ uniquely determined by the preceding input and a fixed, finite portion
(called a @dfn{look-ahead}) of the remaining input. A context-free
grammar can be @dfn{ambiguous}, meaning that there are multiple ways to
apply the grammar rules to get the same inputs. Even unambiguous
grammars can be @dfn{non-deterministic}, meaning that no fixed
grammars can be @dfn{nondeterministic}, meaning that no fixed
look-ahead always suffices to determine the next grammar rule to apply.
With the proper declarations, Bison is also able to parse these more
general context-free grammars, using a technique known as @acronym{GLR}
@@ -2126,7 +2126,7 @@ as @code{sin}, @code{cos}, etc.
It is easy to add new operators to the infix calculator as long as they are
only single-character literals. The lexical analyzer @code{yylex} passes
back all nonnumber characters as tokens, so new grammar rules suffice for
back all nonnumeric characters as tokens, so new grammar rules suffice for
adding a new operator. But we want something more flexible: built-in
functions whose syntax has this form:
@@ -2411,7 +2411,7 @@ getsym (char const *sym_name)
The function @code{yylex} must now recognize variables, numeric values, and
the single-character arithmetic operators. Strings of alphanumeric
characters with a leading non-digit are recognized as either variables or
characters with a leading letter are recognized as either variables or
functions depending on what the symbol table says about them.
The string is passed to @code{getsym} for look up in the symbol table. If
@@ -2782,7 +2782,7 @@ into a separate header file @file{@var{name}.tab.h} which you can include
in the other source files that need it. @xref{Invocation, ,Invoking Bison}.
If you want to write a grammar that is portable to any Standard C
host, you must use only non-null character tokens taken from the basic
host, you must use only nonnull character tokens taken from the basic
execution character set of Standard C@. This set consists of the ten
digits, the 52 lower- and upper-case English letters, and the
characters in the following C-language string:
@@ -3813,7 +3813,7 @@ For instance, if your locations use a file name, you may use
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,
or if the parsing is cut by @code{YYACCEPT} or @code{YYABORT}, all the
or if it returns via @code{YYABORT} or @code{YYACCEPT}, all the
symbols on the stack must be discarded. Even if the parser succeeds, it
must discard the start symbol.
@@ -3862,16 +3862,18 @@ stacked symbols popped during the first phase of error recovery,
incoming terminals during the second phase of error recovery,
@item
the current look-ahead and the entire stack (except the current
right-hand side symbols) when the parser aborts (either via an explicit
call to @code{YYABORT} or @code{YYACCEPT}, or as a consequence of a
failed error recovery or of memory exhaustion), and
right-hand side symbols) when the parser returns immediately, and
@item
the start symbol, when the parser succeeds.
@end itemize
Note that right-hand size symbols of a rule that explicitly triggers a
syntax error via @code{YYERROR} are not reclaimed. As a thumb rule,
destructors are invoked only when you do not have other means to manage
The parser can @dfn{return immediately} because of an explicit call to
@code{YYABORT} or @code{YYACCEPT}, or failed error recovery, or memory
exhaustion.
Right-hand size symbols of a rule that explicitly triggers a syntax
error via @code{YYERROR} are not discarded automatically. As a rule
of thumb, destructors are invoked only when user actions cannot manage
the memory.
@node Expect Decl
@@ -3959,8 +3961,8 @@ may override this restriction with the @code{%start} declaration as follows:
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)
code. Reentrancy is important whenever asynchronous execution is possible;
for example, a non-reentrant program may not be safe to call from a signal
handler. In systems with multiple threads of control, a non-reentrant
for example, a nonreentrant program may not be safe to call from a signal
handler. In systems with multiple threads of control, a nonreentrant
program must be called only within interlocks.
Normally, Bison generates a parser which is not reentrant. This is
@@ -4450,7 +4452,7 @@ The @code{yytname} table is generated only if you use the
@subsection Semantic Values of Tokens
@vindex yylval
In an ordinary (non-reentrant) parser, the semantic value of the token must
In an ordinary (nonreentrant) parser, the semantic value of the token must
be stored into the global variable @code{yylval}. When you are using
just one data type for semantic values, @code{yylval} has that type.
Thus, if the type is @code{int} (the default), you might write this in
@@ -5610,7 +5612,7 @@ pp.@: 615--649 @uref{http://doi.acm.org/10.1145/69622.357187}.
@cindex @acronym{GLR} parsing
@cindex generalized @acronym{LR} (@acronym{GLR}) parsing
@cindex ambiguous grammars
@cindex non-deterministic parsing
@cindex nondeterministic parsing
Bison produces @emph{deterministic} parsers that choose uniquely
when to reduce and which reduction to apply
@@ -5675,10 +5677,10 @@ quadratic worst-case time, and any general (possibly ambiguous)
context-free grammar in cubic worst-case time. However, Bison currently
uses a simpler data structure that requires time proportional to the
length of the input times the maximum number of stacks required for any
prefix of the input. Thus, really ambiguous or non-deterministic
prefix of the input. Thus, really ambiguous or nondeterministic
grammars can require exponential time and space to process. Such badly
behaving examples, however, are not generally of practical interest.
Usually, non-determinism in a grammar is local---the parser is ``in
Usually, nondeterminism in a grammar is local---the parser is ``in
doubt'' only for a few tokens at a time. Therefore, the current data
structure should generally be adequate. On @acronym{LALR}(1) portions of a
grammar, in particular, it is only slightly slower than with the default
@@ -7037,7 +7039,7 @@ The output files @file{@var{output}.hh} and @file{@var{output}.cc}
declare and define the parser class in the namespace @code{yy}. The
class name defaults to @code{parser}, but may be changed using
@samp{%define "parser_class_name" "@var{name}"}. The interface of
this class is detailled below. It can be extended using the
this class is detailed below. It can be extended using the
@code{%parse-param} feature: its semantics is slightly changed since
it describes an additional member of the parser class, and an
additional argument for its constructor.
@@ -7065,7 +7067,7 @@ Get or set the stream used for tracing the parsing. It defaults to
@deftypemethod {parser} {debug_level_type} debug_level ()
@deftypemethodx {parser} {void} set_debug_level (debug_level @var{l})
Get or set the tracing level. Currently its value is either 0, no trace,
or non-zero, full tracing.
or nonzero, full tracing.
@end deftypemethod
@deftypemethod {parser} {void} error (const location_type& @var{l}, const std::string& @var{m})
@@ -7116,7 +7118,7 @@ actually easier to interface with.
@subsection Calc++ --- C++ Calculator
Of course the grammar is dedicated to arithmetics, a single
expression, possibily preceded by variable assignments. An
expression, possibly preceded by variable assignments. An
environment containing possibly predefined variables such as
@code{one} and @code{two}, is exchanged with the parser. An example
of valid input follows.
@@ -7480,7 +7482,7 @@ blank [ \t]
@end example
@noindent
The following paragraph suffices to track locations acurately. Each
The following paragraph suffices to track locations accurately. Each
time @code{yylex} is invoked, the begin position is moved onto the end
position. Then when a pattern is matched, the end position is
advanced of its width. In case it matched ends of lines, the end
@@ -7505,7 +7507,7 @@ preceding tokens. Comments would be treated equally.
The rules are simple, just note the use of the driver to report errors.
It is convenient to use a typedef to shorten
@code{yy::calcxx_parser::token::identifier} into
@code{token::identifier} for isntance.
@code{token::identifier} for instance.
@comment file: calc++-scanner.ll
@example
@@ -7949,7 +7951,7 @@ parser file. @xref{Decl Summary}.
@end deffn
@deffn {Directive} %nonassoc
Bison declaration to assign non-associativity to token(s).
Bison declaration to assign nonassociativity to token(s).
@xref{Precedence Decl, ,Operator Precedence}.
@end deffn

8
tests/cxx-type.at
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@@ -231,7 +231,7 @@ yyerror (ERROR_PARAMETERS)
static Node *
new_nterm (char const *form, Node *child0, Node *child1, Node *child2)
{
Node *node = malloc (sizeof (Node));
Node *node = (Node *) malloc (sizeof (Node));
node->nterm.type = 1;
node->nterm.parents = 0;
node->nterm.form = form;
@@ -250,7 +250,7 @@ new_nterm (char const *form, Node *child0, Node *child1, Node *child2)
static Node *
new_term (char *text)
{
Node *node = malloc (sizeof (Node));
Node *node = (Node *) malloc (sizeof (Node));
node->term.type = 0;
node->term.parents = 0;
node->term.text = text;
@@ -286,7 +286,7 @@ node_to_string (Node *node)
char *buffer;
if (!node)
{
buffer = malloc (1);
buffer = (char *) malloc (1);
buffer[0] = 0;
}
else if (node->node_info.type == 1)
@@ -294,7 +294,7 @@ node_to_string (Node *node)
child0 = node_to_string (node->nterm.children[0]);
child1 = node_to_string (node->nterm.children[1]);
child2 = node_to_string (node->nterm.children[2]);
buffer = malloc (strlen (node->nterm.form) + strlen (child0)
buffer = (char *) malloc (strlen (node->nterm.form) + strlen (child0)
+ strlen (child1) + strlen (child2) + 1);
sprintf (buffer, node->nterm.form, child0, child1, child2);
free (child0);