Bison News
----------
+* Changes in version ?.? (????-??-??):
+
+** Additional yylex/yyparse arguments
+
+ The new directive %param declare additional argument to both yylex
+ and yyparse. The %lex-param, %parse-param, and %param directives
+ support one or more arguments. Instead of
+
+ %lex-param {arg1_type *arg1}
+ %lex-param {arg2_type *arg2}
+ %parse-param {arg1_type *arg1}
+ %parse-param {arg2_type *arg2}
+
+ one may now declare
+
+ %param {arg1_type *arg1} {arg2_type *arg2}
+
+** Java skeleton improvements
+
+ The constants for token names were moved to the Lexer interface.
+ Also, it is possible to add code to the parser's constructors using
+ "%code init" and "%define init_throws".
+
+** C++ skeleton improvements
+
+ The C++ parser features a syntax_error exception, which can be
+ thrown from the scanner or from user rules to raise syntax errors.
+ This facilitates reporting errors caught in sub-functions (e.g.,
+ rejecting too large integral literals from a conversion function
+ used by the scanner, or rejecting invalid combinations from a
+ factory invoked by the user actions).
+
+** Variable api.tokens.prefix
+
+ The variable api.tokens.prefix changes the way tokens are identified in
+ the generated files. This is especially useful to avoid collisions
+ with identifiers in the target language. For instance
+
+ %token FILE for ERROR
+ %define api.tokens.prefix "TOK_"
+ %%
+ start: FILE for ERROR;
+
+ will generate the definition of the symbols TOK_FILE, TOK_for, and
+ TOK_ERROR in the generated sources. In particular, the scanner must
+ use these prefixed token names, although the grammar itself still
+ uses the short names (as in the sample rule given above).
+
+** Variable api.namespace
+
+ The "namespace" variable is renamed "api.namespace". Backward
+ compatibility is ensured, but upgrading is recommended.
+
+** Variable parse.error
+
+ The variable error controls the verbosity of error messages. The
+ use of the %error-verbose directive is deprecated in favor of
+ %define parse.error "verbose".
+
+** Semantic predicates
+
+ The new, experimental, semantic-predicate feature allows actions of
+ the form %?{ BOOLEAN-EXPRESSION }, which cause syntax errors (as for
+ YYERROR) if the expression evaluates to 0, and are evaluated immediately
+ in GLR parsers, rather than being deferred. The result is that they
+ allow the programmer to prune possible parses based on the values of
+ runtime expressions.
+
* Changes in version 2.5.1 (????-??-??):
- ** Several portability problems in the test suite have been fixed:
+ ** Future changes:
- This includes warnings with some compilers, unexpected behavior of
- tools such as diff, warning messages from the test suite itself,
- etc.
+ The next major release will drop support for K&R C.
- __attribute__ is not longer disabled when __STRICT_ANSI__ is defined
- (i.e., when -std is passed to GCC).
+ ** yacc.c: YYBACKUP works as expected.
- ** Warnings during the build procedure have been eliminated.
+ ** glr.c improvements:
- ** Many minor improvements have been made to the manual:
+ *** Location support is eliminated when not requested:
- The layout for grammar has changed to a more compact scheme. Named
- references are motivated. The description of the automaton
- description file is updated.
+ GLR parsers used to include location-related code even when
+ locations were not requested, and therefore not even usable.
- ** YYBACKUP works as expected.
+ *** __attribute__ is preserved:
- ** liby is no longer asking for "rpl_fprintf" on some platforms.
+ __attribute__ is no longer disabled when __STRICT_ANSI__ is defined
+ (i.e., when -std is passed to GCC).
- ** Several Java fixes:
+ ** lalr1.java: several fixes:
The Java parser no longer throws ArrayIndexOutOfBoundsException if
the first token leads to a syntax error. Some minor clean ups.
methods) accept new arguments for line and column. Several issues
in the documentation were fixed.
+ ** liby is no longer asking for "rpl_fprintf" on some platforms.
+
+ ** Changes in the manual:
+
+ *** %printer is documented
+
+ The %printer directive, supported since at least Bison 1.50, is
+ finally documented. The %mfcalc example is extended to demonstrate
+ its use of printer.
+
+ The C++ parsers now also support yyoutput (as an alias to
+ debug_stream ()) for consistency with the C skeletons.
+
+ *** Several improvements have been made:
+
+ The layout for grammar excerpts was changed to a more compact
+ scheme. Named references are motivated. The description of the
+ automaton description file (*.output) is updated to the current
+ format. Incorrect index entries were fixed. Some other errors were
+ fixed.
+
+ ** Changes to the build system:
+
+ *** Warnings during the build procedure have been eliminated.
+
+ *** Several portability problems in the test suite have been fixed:
+
+ This includes warnings with some compilers, unexpected behavior of
+ tools such as diff, warning messages from the test suite itself,
+ etc.
+
+ *** The install-pdf target work properly:
+
+ Running "make install-pdf" (or -dvi, -html, -info, and -ps) no
+ longer halts in the middle of its course.
+
* Changes in version 2.5 (2011-05-14):
** Grammar symbol names can now contain non-initial dashes:
if the symbols have destructors. For instance:
exp: exp "?" exp ":" exp { $1 ? $1 : $3; }
- | exp "+" exp
- ;
+ | exp "+" exp
+ ;
will trigger a warning about $$ and $5 in the first rule, and $3 in
the second ($1 is copied to $$ by the default rule). This example
most likely contains three errors, and could be rewritten as:
exp: exp "?" exp ":" exp
- { $$ = $1 ? $3 : $5; free ($1 ? $5 : $3); free ($1); }
- | exp "+" exp
- { $$ = $1 ? $1 : $3; if ($1) free ($3); }
- ;
+ { $$ = $1 ? $3 : $5; free ($1 ? $5 : $3); free ($1); }
+ | exp "+" exp
+ { $$ = $1 ? $1 : $3; if ($1) free ($3); }
+ ;
However, if the original actions were really intended, memory leaks
and all, the warnings can be suppressed by letting Bison believe the
values are used, e.g.:
exp: exp "?" exp ":" exp { $1 ? $1 : $3; (void) ($$, $5); }
- | exp "+" exp { $$ = $1; (void) $3; }
- ;
+ | exp "+" exp { $$ = $1; (void) $3; }
+ ;
If there are mid-rule actions, the warning is issued if no action
uses it. The following triggers no warning: $1 and $3 are used.
In agreement with POSIX and with other Yaccs, leaving a default
action is valid when $$ is untyped, and $1 typed:
- untyped: ... typed;
+ untyped: ... typed;
but the converse remains an error:
- typed: ... untyped;
+ typed: ... untyped;
** Values of mid-rule actions
The following code:
- foo: { ... } { $$ = $1; } ...
+ foo: { ... } { $$ = $1; } ...
was incorrectly rejected: $1 is defined in the second mid-rule
action, and is equal to the $$ of the first mid-rule action.
** The output file does not define const, as this caused problems when used
with common autoconfiguration schemes. If you still use ancient compilers
that lack const, compile with the equivalent of the C compiler option
- `-Dconst='. autoconf's AC_C_CONST macro provides one way to do this.
+ `-Dconst='. Autoconf's AC_C_CONST macro provides one way to do this.
** Added `-g' and `--graph'.
\f
* Changes in version 1.26:
- ** Bison now uses automake.
+ ** Bison now uses Automake.
** New mailing lists: <bug-bison@gnu.org> and <help-bison@gnu.org>.
** Tokens can now be specified as multiple-character strings: for
example, you could use "<=" for a token which looks like <=, instead
- of chosing a name like LESSEQ.
+ of choosing a name like LESSEQ.
** The %token_table declaration says to write a table of tokens (names
and numbers) into the parser file. The yylex function can use this
Output file does not redefine const for C++.
- Local Variables:
- mode: outline
- End:
-
-----
Copyright (C) 1995-2012 Free Software Foundation, Inc.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+ LocalWords: yacc YYBACKUP glr GCC lalr ArrayIndexOutOfBoundsException nullptr
+ LocalWords: cplusplus liby rpl fprintf mfcalc Wyacc stmt cond expr mk sym lr
+ LocalWords: IELR ielr Lookahead YYERROR nonassoc LALR's api lookaheads yychar
+ LocalWords: destructor lookahead YYRHSLOC YYLLOC Rhs ifndef YYFAIL cpp sr rr
+ LocalWords: preprocessor initializer Wno Wnone Werror FreeBSD prec livelocks
+ LocalWords: Solaris AIX UX RHEL Tru LHS gcc's Wundef YYENABLE NLS YYLTYPE VCG
+ LocalWords: yyerror cpp's Wunused yylval yylloc prepend yyparse yylex yypush
+ LocalWords: Graphviz xml nonterminals midrule destructor's YYSTYPE typedef ly
+ LocalWords: CHR chr printf stdout namespace preprocessing enum pre include's
+ LocalWords: YYRECOVERING nonfree destructors YYABORT YYACCEPT params enums de
+ LocalWords: struct yystype DJGPP lex param Haible NUM alloca YYSTACK NUL goto
+ LocalWords: YYMAXDEPTH Unescaped UCNs YYLTYPE's yyltype typedefs inline Yaccs
+ LocalWords: Heriyanto Reenable dprec Hilfinger Eggert MYEOF Folle Menezes EOF
+ LocalWords: Lackovic define's itemset Groff Gettext malloc NEWS'ed YYDEBUG
+ LocalWords: namespaces strerror const autoconfiguration Dconst Autoconf's FDL
+ LocalWords: Automake TMPDIR LESSEQ
+
+ Local Variables:
+ mode: outline
+ End:
bootstrap_post_import_hook()
{
+ # Massage lib/gnulib.mk before using it later in the bootstrapping process.
+ etc/prefix-gnulib-mk --lib-name=$gnulib_name lib/$gnulib_mk
+
# Ensure that ChangeLog exists, for automake.
test -f ChangeLog || touch ChangeLog
}
# the bootstrap entry from the file .x-update-copyright, and add any
# needed copyright years to the copyright statement in the bootstrap
# script.
- # FIXME: temporary bootstrap_sync=true
+ bootstrap_sync=true
# releases, we want to be able run make dist without being required to
# add a bogus NEWS entry. In that case, the version string
# automatically contains a dash, which we also let disable gnits.
-AM_INIT_AUTOMAKE([1.11.1 dist-xz silent-rules]
+AM_INIT_AUTOMAKE([1.11.1 dist-xz nostdinc
+ color-tests parallel-tests
+ silent-rules]
m4_bmatch(m4_defn([AC_PACKAGE_VERSION]), [[-_]],
[gnu], [gnits]))
AM_SILENT_RULES([yes])
, [enable_yacc=yes])
case $enable_yacc in
yes)
- YACC_SCRIPT=yacc
- YACC_LIBRARY=liby.a;;
+ YACC_SCRIPT=src/yacc
+ YACC_LIBRARY=lib/liby.a;;
*)
YACC_SCRIPT=
YACC_LIBRARY=;;
# Checks for programs.
AC_PROG_LEX
+ if test "$FLEX" != yes; then
+ AC_MSG_ERROR([Flex is required])
+ fi
AC_PROG_YACC
AC_PROG_RANLIB
AC_PROG_GNU_M4
AC_DEFINE_UNQUOTED([M4], ["$M4"], [Define to the GNU M4 executable name.])
AC_DEFINE_UNQUOTED([M4_GNU_OPTION], ["$M4_GNU"], [Define to "-g" if GNU M4
supports -g, otherwise to "".])
+AC_PATH_PROG([PERL], [perl])
+if test -z "$PERL"; then
+ AC_MSG_ERROR([perl not found])
+fi
AM_MISSING_PROG([HELP2MAN], [help2man])
AC_PATH_PROG([XSLTPROC], [xsltproc])
AC_SUBST([XSLTPROC])
# Initialize the test suite.
AC_CONFIG_TESTDIR(tests)
-AC_CONFIG_FILES([tests/Makefile tests/atlocal])
+AC_CONFIG_FILES([tests/atlocal])
AC_CONFIG_FILES([tests/bison], [chmod +x tests/bison])
AC_CHECK_PROGS([VALGRIND], [valgrind])
AM_MISSING_PROG([AUTOM4TE], [autom4te])
# Needed by tests/atlocal.in.
AC_SUBST([GCC])
-gt_JAVACOMP([1.3])
+gt_JAVACOMP([1.3], [1.4])
gt_JAVAEXEC
+# We use gnulib, but from lib/local.mk instead of lib/Makefile.am.
+# So prefix paths with lib/. See also etc/prefix-gnulib-mk.
+gl_LIBOBJS=`echo "$gl_LIBOBJS" | sed -e 's, , lib/,g'`
+# Listing the names of the variables to prefix is error-prone.
+# Rather, adjust all the AC_SUBST variables whose name ends in '_H',
+# and whose content ends in '.h'.
+for ac_var in $ac_subst_vars
+do
+ eval "ac_val=\$$ac_var"
+ case $ac_var=$ac_val in
+ (*_H=*.h) eval "$ac_var=lib/\$$ac_var";;
+ esac
+done
AC_CONFIG_FILES([Makefile
- build-aux/Makefile
- po/Makefile.in
- data/Makefile
- etc/Makefile
- examples/Makefile
- examples/calc++/Makefile
- lib/Makefile src/Makefile
- doc/Makefile
- doc/yacc.1])
+ po/Makefile.in
+ doc/yacc.1])
AC_OUTPUT
# --------------------
# Expansion of $<TYPE>$.
m4_define([b4_lhs_value],
-[((*yyvalp)[]m4_ifval([$1], [.$1]))])
+[b4_symbol_value([(*yyvalp)], [$1])])
+
+
+# b4_rhs_data(RULE-LENGTH, NUM)
+# -----------------------------
+# Expand to the semantic stack place that contains value and location
+# of symbol number NUM in a rule of length RULE-LENGTH.
+m4_define([b4_rhs_data],
+[((yyGLRStackItem const *)yyvsp)@{YYFILL (b4_subtract([$2], [$1]))@}.yystate])
# b4_rhs_value(RULE-LENGTH, NUM, [TYPE])
# Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
# symbols on RHS.
m4_define([b4_rhs_value],
-[(((yyGLRStackItem const *)yyvsp)@{YYFILL (($2) - ($1))@}.yystate.yysemantics.yysval[]m4_ifval([$3], [.$3]))])
+[b4_symbol_value([b4_rhs_data([$1], [$2]).yysemantics.yysval], [$3])])
# Expansion of @NUM, where the current rule has RULE-LENGTH symbols
# on RHS.
m4_define([b4_rhs_location],
-[(((yyGLRStackItem const *)yyvsp)@{YYFILL (($2) - ($1))@}.yystate.yyloc)])
+[(b4_rhs_data([$1], [$2]).yyloc)])
[[typedef int YYSTYPE;
# define YYSTYPE_IS_TRIVIAL 1]])])[
#endif
-
+ ]b4_locations_if([[
#if ! defined YYLTYPE && ! defined YYLTYPE_IS_DECLARED
typedef struct YYLTYPE
{
- ]b4_locations_if([
int first_line;
int first_column;
int last_line;
int last_column;
- ],[
- char yydummy;
- ])[
} YYLTYPE;
# define YYLTYPE_IS_DECLARED 1
# define YYLTYPE_IS_TRIVIAL 1
#endif
-
+ ]])[
]b4_percent_code_get([[provides]])[]dnl
])
b4_defines_if([[#include "@basename(]b4_spec_defines_file[@)"]],
- [b4_shared_declarations])[
+ [b4_shared_declarations])[
/* Enabling traces. */
#ifndef YYDEBUG
-# define YYDEBUG ]b4_debug_flag[
+# define YYDEBUG ]b4_parse_trace_if([1], [0])[
#endif
/* Enabling verbose error messages. */
# undef YYERROR_VERBOSE
# define YYERROR_VERBOSE 1
#else
-# define YYERROR_VERBOSE ]b4_error_verbose_flag[
+# define YYERROR_VERBOSE ]b4_error_verbose_if([1], [0])[
#endif
/* Enabling the token table. */
#define YYUNDEFTOK ]b4_undef_token_number[
#define YYMAXUTOK ]b4_user_token_number_max[
-#define YYTRANSLATE(YYX) \
+#define YYTRANSLATE(YYX) \
((unsigned int) (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)
/* YYTRANSLATE[YYLEX] -- Bison symbol number corresponding to YYLEX. */
};
#if YYDEBUG
-/* YYPRHS[YYN] -- Index of the first RHS symbol of rule number YYN in
- YYRHS. */
-static const ]b4_int_type_for([b4_prhs])[ yyprhs[] =
-{
- ]b4_prhs[
-};
-
-/* YYRHS -- A `-1'-separated list of the rules' RHS. */
-static const ]b4_int_type_for([b4_rhs])[ yyrhs[] =
-{
- ]b4_rhs[
-};
-
/* YYRLINE[YYN] -- source line where rule number YYN was defined. */
static const ]b4_int_type_for([b4_rline])[ yyrline[] =
{
};
#endif
-/* YYR1[YYN] -- Symbol number of symbol that rule YYN derives. */
-static const ]b4_int_type_for([b4_r1])[ yyr1[] =
-{
- ]b4_r1[
-};
+#define YYPACT_NINF ]b4_pact_ninf[
+#define YYTABLE_NINF ]b4_table_ninf[
-/* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN. */
-static const ]b4_int_type_for([b4_r2])[ yyr2[] =
-{
- ]b4_r2[
-};
+]b4_parser_tables_define[
/* YYDPREC[RULE-NUM] -- Dynamic precedence of rule #RULE-NUM (0 if none). */
static const ]b4_int_type_for([b4_dprec])[ yydprec[] =
]b4_merger[
};
-/* YYDEFACT[S] -- default reduction number in state S. Performed when
- YYTABLE doesn't specify something else to do. Zero means the default
- is an error. */
-static const ]b4_int_type_for([b4_defact])[ yydefact[] =
-{
- ]b4_defact[
-};
-
-/* YYPDEFGOTO[NTERM-NUM]. */
-static const ]b4_int_type_for([b4_defgoto])[ yydefgoto[] =
-{
- ]b4_defgoto[
-};
-
-/* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
- STATE-NUM. */
-#define YYPACT_NINF ]b4_pact_ninf[
-static const ]b4_int_type_for([b4_pact])[ yypact[] =
-{
- ]b4_pact[
-};
-
-/* YYPGOTO[NTERM-NUM]. */
-static const ]b4_int_type_for([b4_pgoto])[ yypgoto[] =
-{
- ]b4_pgoto[
-};
-
-/* YYTABLE[YYPACT[STATE-NUM]]. What to do in state STATE-NUM. If
- positive, shift that token. If negative, reduce the rule which
- number is the opposite. If YYTABLE_NINF, syntax error. */
-#define YYTABLE_NINF ]b4_table_ninf[
-static const ]b4_int_type_for([b4_table])[ yytable[] =
+/* YYIMMEDIATE[RULE-NUM] -- True iff rule #RULE-NUM is not to be deferred, as
+ in the case of predicates. */
+static const yybool yyimmediate[] =
{
- ]b4_table[
+ ]b4_immediate[
};
/* YYCONFLP[YYPACT[STATE-NUM]] -- Pointer into YYCONFL of start of
{
]b4_conflicting_rules[
};
-
-static const ]b4_int_type_for([b4_check])[ yycheck[] =
-{
- ]b4_check[
-};
-
-/* YYSTOS[STATE-NUM] -- The (internal number of the) accessing
- symbol of state STATE-NUM. */
-static const ]b4_int_type_for([b4_stos])[ yystos[] =
-{
- ]b4_stos[
-};
-
\f
/* Prevent warning if -Wmissing-prototypes. */
]b4_c_ansi_function_decl([yyparse], [int], b4_parse_param)[
]b4_locations_if([[
#define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
#ifndef YYLLOC_DEFAULT
-# define YYLLOC_DEFAULT(Current, Rhs, N) \
- do \
- if (YYID (N)) \
- { \
- (Current).first_line = YYRHSLOC (Rhs, 1).first_line; \
- (Current).first_column = YYRHSLOC (Rhs, 1).first_column; \
- (Current).last_line = YYRHSLOC (Rhs, N).last_line; \
- (Current).last_column = YYRHSLOC (Rhs, N).last_column; \
- } \
- else \
- { \
- (Current).first_line = (Current).last_line = \
- YYRHSLOC (Rhs, 0).last_line; \
- (Current).first_column = (Current).last_column = \
- YYRHSLOC (Rhs, 0).last_column; \
- } \
+# define YYLLOC_DEFAULT(Current, Rhs, N) \
+ do \
+ if (YYID (N)) \
+ { \
+ (Current).first_line = YYRHSLOC (Rhs, 1).first_line; \
+ (Current).first_column = YYRHSLOC (Rhs, 1).first_column; \
+ (Current).last_line = YYRHSLOC (Rhs, N).last_line; \
+ (Current).last_column = YYRHSLOC (Rhs, N).last_column; \
+ } \
+ else \
+ { \
+ (Current).first_line = (Current).last_line = \
+ YYRHSLOC (Rhs, 0).last_line; \
+ (Current).first_column = (Current).last_column = \
+ YYRHSLOC (Rhs, 0).last_column; \
+ } \
while (YYID (0))
/* YY_LOCATION_PRINT -- Print the location on the stream.
This macro was not mandated originally: define only if we know
we won't break user code: when these are the locations we know. */
-# define YY_LOCATION_PRINT(File, Loc) \
- fprintf (File, "%d.%d-%d.%d", \
- (Loc).first_line, (Loc).first_column, \
- (Loc).last_line, (Loc).last_column)
+# define YY_LOCATION_PRINT(File, Loc) \
+ fprintf (File, "%d.%d-%d.%d", \
+ (Loc).first_line, (Loc).first_column, \
+ (Loc).last_line, (Loc).last_column)
#endif
]],[
#ifndef YYLLOC_DEFAULT
#define b4_prefix[]char yychar
#define b4_prefix[]lval yylval
#define b4_prefix[]lloc yylloc])],
- [YYSTYPE yylval;
-
- YYLTYPE yylloc;
+ [YYSTYPE yylval;]b4_locations_if([[
+ YYLTYPE yylloc;]])[
int yynerrs;
int yychar;])[
typedef enum { yyok, yyaccept, yyabort, yyerr } YYRESULTTAG;
-#define YYCHK(YYE) \
- do { YYRESULTTAG yyflag = YYE; if (yyflag != yyok) return yyflag; } \
- while (YYID (0))
+#define YYCHK(YYE) \
+ do { \
+ YYRESULTTAG yychk_flag = YYE; \
+ if (yychk_flag != yyok) \
+ return yychk_flag; \
+ } while (YYID (0))
#if YYDEBUG
# define YYFPRINTF fprintf
# endif
-# define YYDPRINTF(Args) \
-do { \
- if (yydebug) \
- YYFPRINTF Args; \
-} while (YYID (0))
+# define YYDPRINTF(Args) \
+ do { \
+ if (yydebug) \
+ YYFPRINTF Args; \
+ } while (YYID (0))
]b4_yy_symbol_print_generate([b4_c_ansi_function_def])[
-# define YY_SYMBOL_PRINT(Title, Type, Value, Location) \
-do { \
- if (yydebug) \
- { \
- YYFPRINTF (stderr, "%s ", Title); \
+# define YY_SYMBOL_PRINT(Title, Type, Value, Location) \
+ do { \
+ if (yydebug) \
+ { \
+ YYFPRINTF (stderr, "%s ", Title); \
yy_symbol_print (stderr, Type, Value]b4_locuser_args([Location])[); \
- YYFPRINTF (stderr, "\n"); \
- } \
-} while (YYID (0))
+ YYFPRINTF (stderr, "\n"); \
+ } \
+ } while (YYID (0))
/* Nonzero means print parse trace. It is left uninitialized so that
multiple parsers can coexist. */
#endif /* !YYDEBUG */
/* YYINITDEPTH -- initial size of the parser's stacks. */
-#ifndef YYINITDEPTH
+#ifndef YYINITDEPTH
# define YYINITDEPTH ]b4_stack_depth_init[
#endif
#define YYHEADROOM 2
#ifndef YYSTACKEXPANDABLE
-# if (! defined __cplusplus \
- || (]b4_locations_if([[defined YYLTYPE_IS_TRIVIAL && YYLTYPE_IS_TRIVIAL \
- && ]])[defined YYSTYPE_IS_TRIVIAL && YYSTYPE_IS_TRIVIAL))
# define YYSTACKEXPANDABLE 1
-# else
-# define YYSTACKEXPANDABLE 0
-# endif
#endif
#if YYSTACKEXPANDABLE
-# define YY_RESERVE_GLRSTACK(Yystack) \
- do { \
- if (Yystack->yyspaceLeft < YYHEADROOM) \
- yyexpandGLRStack (Yystack); \
+# define YY_RESERVE_GLRSTACK(Yystack) \
+ do { \
+ if (Yystack->yyspaceLeft < YYHEADROOM) \
+ yyexpandGLRStack (Yystack); \
} while (YYID (0))
#else
-# define YY_RESERVE_GLRSTACK(Yystack) \
- do { \
- if (Yystack->yyspaceLeft < YYHEADROOM) \
- yyMemoryExhausted (Yystack); \
+# define YY_RESERVE_GLRSTACK(Yystack) \
+ do { \
+ if (Yystack->yyspaceLeft < YYHEADROOM) \
+ yyMemoryExhausted (Yystack); \
} while (YYID (0))
#endif
char const *yyp = yystr;
for (;;)
- switch (*++yyp)
- {
- case '\'':
- case ',':
- goto do_not_strip_quotes;
-
- case '\\':
- if (*++yyp != '\\')
- goto do_not_strip_quotes;
- /* Fall through. */
- default:
- if (yyres)
- yyres[yyn] = *yyp;
- yyn++;
- break;
-
- case '"':
- if (yyres)
- yyres[yyn] = '\0';
- return yyn;
- }
+ switch (*++yyp)
+ {
+ case '\'':
+ case ',':
+ goto do_not_strip_quotes;
+
+ case '\\':
+ if (*++yyp != '\\')
+ goto do_not_strip_quotes;
+ /* Fall through. */
+ default:
+ if (yyres)
+ yyres[yyn] = *yyp;
+ yyn++;
+ break;
+
+ case '"':
+ if (yyres)
+ yyres[yyn] = '\0';
+ return yyn;
+ }
do_not_strip_quotes: ;
}
typedef int yyRuleNum;
/** Grammar symbol */
-typedef short int yySymbol;
+typedef int yySymbol;
/** Item references, as in LALR(1) machine */
typedef short int yyItemNum;
yyStateNum yylrState;
/** Preceding state in this stack */
yyGLRState* yypred;
- /** Source position of the first token produced by my symbol */
+ /** Source position of the last token produced by my symbol */
size_t yyposn;
union {
/** First in a chain of alternative reductions producing the
yySemanticOption* yyfirstVal;
/** Semantic value for this state. */
YYSTYPE yysval;
- } yysemantics;
+ } yysemantics;]b4_locations_if([[
/** Source location for this state. */
- YYLTYPE yyloc;
+ YYLTYPE yyloc;]])[
};
struct yyGLRStateSet {
yyGLRState* yystate;
/** The lookahead for this reduction. */
int yyrawchar;
- YYSTYPE yyval;
- YYLTYPE yyloc;
+ YYSTYPE yyval;]b4_locations_if([[
+ YYLTYPE yyloc;]])[
/** Next sibling in chain of options. To facilitate merging,
* options are chained in decreasing order by address. */
yySemanticOption* yynext;
[
int yyerrcnt;
int yyrawchar;
- YYSTYPE yyval;
- YYLTYPE yyloc;
+ YYSTYPE yyval;]b4_locations_if([[
+ YYLTYPE yyloc;]])[
])[
YYJMP_BUF yyexception_buffer;
yyGLRStackItem* yyitems;
s = yyvsp[yylow0].yystate.yypred;
for (i = yylow0-1; i >= yylow1; i -= 1)
{
- YYASSERT (s->yyresolved);
- yyvsp[i].yystate.yyresolved = yytrue;
- yyvsp[i].yystate.yysemantics.yysval = s->yysemantics.yysval;]b4_locations_if([[
+#if YYDEBUG
+ yyvsp[i].yystate.yylrState = s->yylrState;
+#endif
+ yyvsp[i].yystate.yyresolved = s->yyresolved;
+ if (s->yyresolved)
+ yyvsp[i].yystate.yysemantics.yysval = s->yysemantics.yysval;
+ else
+ /* The effect of using yysval or yyloc (in an immediate rule) is
+ * undefined. */
- yyvsp[i].yystate.yysemantics.yyfirstVal = YY_NULL;
- yyvsp[i].yystate.yyloc = s->yyloc;
++ yyvsp[i].yystate.yysemantics.yyfirstVal = YY_NULL;]b4_locations_if([[
+ yyvsp[i].yystate.yyloc = s->yyloc;]])[
s = yyvsp[i].yystate.yypred = s->yypred;
}
}
* yyerr for YYERROR, yyabort for YYABORT. */
/*ARGSUSED*/ static YYRESULTTAG
yyuserAction (yyRuleNum yyn, int yyrhslen, yyGLRStackItem* yyvsp,
- yyGLRStack* yystackp,
- YYSTYPE* yyvalp]b4_locuser_formals[)
+ yyGLRStack* yystackp,
+ YYSTYPE* yyvalp]b4_locuser_formals[)
{
yybool yynormal __attribute__ ((__unused__)) =
(yystackp->yysplitPoint == YY_NULL);
int yylow;
-]b4_parse_param_use[]dnl
+]b4_parse_param_use([yyvalp], [yylocp])dnl
[# undef yyerrok
# define yyerrok (yystackp->yyerrState = 0)
# undef YYACCEPT
# undef YYFILL
# define YYFILL(N) yyfill (yyvsp, &yylow, N, yynormal)
# undef YYBACKUP
-# define YYBACKUP(Token, Value) \
+# define YYBACKUP(Token, Value) \
return yyerror (]b4_yyerror_args[YY_("syntax error: cannot back up")), \
- yyerrok, yyerr
+ yyerrok, yyerr
yylow = 1;
if (yyrhslen == 0)
}
}
- /* Bison grammar-table manipulation. */
+ /* Bison grammar-table manipulation. */
]b4_yydestruct_generate([b4_c_ansi_function_def])[
{
if (yys->yyresolved)
yydestruct (yymsg, yystos[yys->yylrState],
- &yys->yysemantics.yysval]b4_locuser_args([&yys->yyloc])[);
+ &yys->yysemantics.yysval]b4_locuser_args([&yys->yyloc])[);
else
{
#if YYDEBUG
if (yydebug)
- {
- if (yys->yysemantics.yyfirstVal)
- YYFPRINTF (stderr, "%s unresolved ", yymsg);
- else
- YYFPRINTF (stderr, "%s incomplete ", yymsg);
- yy_symbol_print (stderr, yystos[yys->yylrState],
- YY_NULL]b4_locuser_args([&yys->yyloc])[);
- YYFPRINTF (stderr, "\n");
- }
+ {
+ if (yys->yysemantics.yyfirstVal)
+ YYFPRINTF (stderr, "%s unresolved ", yymsg);
+ else
+ YYFPRINTF (stderr, "%s incomplete ", yymsg);
+ yy_symbol_print (stderr, yystos[yys->yylrState],
+ YY_NULL]b4_locuser_args([&yys->yyloc])[);
+ YYFPRINTF (stderr, "\n");
+ }
#endif
if (yys->yysemantics.yyfirstVal)
- {
- yySemanticOption *yyoption = yys->yysemantics.yyfirstVal;
- yyGLRState *yyrh;
- int yyn;
- for (yyrh = yyoption->yystate, yyn = yyrhsLength (yyoption->yyrule);
- yyn > 0;
- yyrh = yyrh->yypred, yyn -= 1)
- yydestroyGLRState (yymsg, yyrh]b4_user_args[);
- }
+ {
+ yySemanticOption *yyoption = yys->yysemantics.yyfirstVal;
+ yyGLRState *yyrh;
+ int yyn;
+ for (yyrh = yyoption->yystate, yyn = yyrhsLength (yyoption->yyrule);
+ yyn > 0;
+ yyrh = yyrh->yypred, yyn -= 1)
+ yydestroyGLRState (yymsg, yyrh]b4_user_args[);
+ }
}
}
-/** Left-hand-side symbol for rule #RULE. */
+/** Left-hand-side symbol for rule #YYRULE. */
static inline yySymbol
yylhsNonterm (yyRuleNum yyrule)
{
#define yypact_value_is_default(yystate) \
]b4_table_value_equals([[pact]], [[yystate]], [b4_pact_ninf])[
-/** True iff LR state STATE has only a default reduction (regardless
+/** True iff LR state YYSTATE has only a default reduction (regardless
* of token). */
static inline yybool
yyisDefaultedState (yyStateNum yystate)
return yypact_value_is_default (yypact[yystate]);
}
-/** The default reduction for STATE, assuming it has one. */
+/** The default reduction for YYSTATE, assuming it has one. */
static inline yyRuleNum
yydefaultAction (yyStateNum yystate)
{
* R < 0: Reduce on rule -R.
* R = 0: Error.
* R > 0: Shift to state R.
- * Set *CONFLICTS to a pointer into yyconfl to 0-terminated list of
- * conflicting reductions.
+ * Set *YYCONFLICTS to a pointer into yyconfl to a 0-terminated list
+ * of conflicting reductions.
*/
static inline void
yygetLRActions (yyStateNum yystate, int yytoken,
- int* yyaction, const short int** yyconflicts)
+ int* yyaction, const short int** yyconflicts)
{
int yyindex = yypact[yystate] + yytoken;
if (yypact_value_is_default (yypact[yystate])
static inline yyStateNum
yyLRgotoState (yyStateNum yystate, yySymbol yylhs)
{
- int yyr;
- yyr = yypgoto[yylhs - YYNTOKENS] + yystate;
+ int yyr = yypgoto[yylhs - YYNTOKENS] + yystate;
if (0 <= yyr && yyr <= YYLAST && yycheck[yyr] == yystate)
return yytable[yyr];
else
return yyaction == 0;
}
- /* GLRStates */
+ /* GLRStates */
-/** Return a fresh GLRStackItem. Callers should call
- * YY_RESERVE_GLRSTACK afterwards to make sure there is sufficient
- * headroom. */
+/** Return a fresh GLRStackItem in YYSTACKP. The item is an LR state
+ * if YYISSTATE, and otherwise a semantic option. Callers should call
+ * YY_RESERVE_GLRSTACK afterwards to make sure there is sufficient
+ * headroom. */
static inline yyGLRStackItem*
yynewGLRStackItem (yyGLRStack* yystackp, yybool yyisState)
}
/** Add a new semantic action that will execute the action for rule
- * RULENUM on the semantic values in RHS to the list of
- * alternative actions for STATE. Assumes that RHS comes from
- * stack #K of *STACKP. */
+ * YYRULE on the semantic values in YYRHS to the list of
+ * alternative actions for YYSTATE. Assumes that YYRHS comes from
+ * stack #YYK of *YYSTACKP. */
static void
yyaddDeferredAction (yyGLRStack* yystackp, size_t yyk, yyGLRState* yystate,
- yyGLRState* rhs, yyRuleNum yyrule)
+ yyGLRState* yyrhs, yyRuleNum yyrule)
{
yySemanticOption* yynewOption =
&yynewGLRStackItem (yystackp, yyfalse)->yyoption;
- yynewOption->yystate = rhs;
+ yynewOption->yystate = yyrhs;
yynewOption->yyrule = yyrule;
if (yystackp->yytops.yylookaheadNeeds[yyk])
{
YY_RESERVE_GLRSTACK (yystackp);
}
- /* GLRStacks */
+ /* GLRStacks */
-/** Initialize SET to a singleton set containing an empty stack. */
+/** Initialize YYSET to a singleton set containing an empty stack. */
static yybool
yyinitStateSet (yyGLRStateSet* yyset)
{
YYFREE (yyset->yylookaheadNeeds);
}
-/** Initialize STACK to a single empty stack, with total maximum
- * capacity for all stacks of SIZE. */
+/** Initialize *YYSTACKP to a single empty stack, with total maximum
+ * capacity for all stacks of YYSIZE. */
static yybool
yyinitGLRStack (yyGLRStack* yystackp, size_t yysize)
{
# define YYRELOC(YYFROMITEMS,YYTOITEMS,YYX,YYTYPE) \
&((YYTOITEMS) - ((YYFROMITEMS) - (yyGLRStackItem*) (YYX)))->YYTYPE
-/** If STACK is expandable, extend it. WARNING: Pointers into the
+/** If *YYSTACKP is expandable, extend it. WARNING: Pointers into the
stack from outside should be considered invalid after this call.
We always expand when there are 1 or fewer items left AFTER an
allocation, so that we can avoid having external pointers exist
{
*yyp1 = *yyp0;
if (*(yybool *) yyp0)
- {
- yyGLRState* yys0 = &yyp0->yystate;
- yyGLRState* yys1 = &yyp1->yystate;
- if (yys0->yypred != YY_NULL)
- yys1->yypred =
- YYRELOC (yyp0, yyp1, yys0->yypred, yystate);
- if (! yys0->yyresolved && yys0->yysemantics.yyfirstVal != YY_NULL)
- yys1->yysemantics.yyfirstVal =
- YYRELOC(yyp0, yyp1, yys0->yysemantics.yyfirstVal, yyoption);
- }
+ {
+ yyGLRState* yys0 = &yyp0->yystate;
+ yyGLRState* yys1 = &yyp1->yystate;
+ if (yys0->yypred != YY_NULL)
+ yys1->yypred =
+ YYRELOC (yyp0, yyp1, yys0->yypred, yystate);
+ if (! yys0->yyresolved && yys0->yysemantics.yyfirstVal != YY_NULL)
+ yys1->yysemantics.yyfirstVal =
+ YYRELOC(yyp0, yyp1, yys0->yysemantics.yyfirstVal, yyoption);
+ }
else
- {
- yySemanticOption* yyv0 = &yyp0->yyoption;
- yySemanticOption* yyv1 = &yyp1->yyoption;
- if (yyv0->yystate != YY_NULL)
- yyv1->yystate = YYRELOC (yyp0, yyp1, yyv0->yystate, yystate);
- if (yyv0->yynext != YY_NULL)
- yyv1->yynext = YYRELOC (yyp0, yyp1, yyv0->yynext, yyoption);
- }
+ {
+ yySemanticOption* yyv0 = &yyp0->yyoption;
+ yySemanticOption* yyv1 = &yyp1->yyoption;
+ if (yyv0->yystate != YY_NULL)
+ yyv1->yystate = YYRELOC (yyp0, yyp1, yyv0->yystate, yystate);
+ if (yyv0->yynext != YY_NULL)
+ yyv1->yynext = YYRELOC (yyp0, yyp1, yyv0->yynext, yyoption);
+ }
}
if (yystackp->yysplitPoint != YY_NULL)
yystackp->yysplitPoint = YYRELOC (yystackp->yyitems, yynewItems,
- yystackp->yysplitPoint, yystate);
+ yystackp->yysplitPoint, yystate);
for (yyn = 0; yyn < yystackp->yytops.yysize; yyn += 1)
if (yystackp->yytops.yystates[yyn] != YY_NULL)
yystackp->yytops.yystates[yyn] =
- YYRELOC (yystackp->yyitems, yynewItems,
- yystackp->yytops.yystates[yyn], yystate);
+ YYRELOC (yystackp->yyitems, yynewItems,
+ yystackp->yytops.yystates[yyn], yystate);
YYFREE (yystackp->yyitems);
yystackp->yyitems = yynewItems;
yystackp->yynextFree = yynewItems + yysize;
yyfreeStateSet (&yystackp->yytops);
}
-/** Assuming that S is a GLRState somewhere on STACK, update the
- * splitpoint of STACK, if needed, so that it is at least as deep as
- * S. */
+/** Assuming that YYS is a GLRState somewhere on *YYSTACKP, update the
+ * splitpoint of *YYSTACKP, if needed, so that it is at least as deep as
+ * YYS. */
static inline void
yyupdateSplit (yyGLRStack* yystackp, yyGLRState* yys)
{
yystackp->yysplitPoint = yys;
}
-/** Invalidate stack #K in STACK. */
+/** Invalidate stack #YYK in *YYSTACKP. */
static inline void
yymarkStackDeleted (yyGLRStack* yystackp, size_t yyk)
{
yystackp->yytops.yystates[yyk] = YY_NULL;
}
-/** Undelete the last stack that was marked as deleted. Can only be
- done once after a deletion, and only when all other stacks have
+/** Undelete the last stack in *YYSTACKP that was marked as deleted. Can
+ only be done once after a deletion, and only when all other stacks have
been deleted. */
static void
yyundeleteLastStack (yyGLRStack* yystackp)
while (yyj < yystackp->yytops.yysize)
{
if (yystackp->yytops.yystates[yyi] == YY_NULL)
- {
- if (yyi == yyj)
- {
- YYDPRINTF ((stderr, "Removing dead stacks.\n"));
- }
- yystackp->yytops.yysize -= 1;
- }
+ {
+ if (yyi == yyj)
+ {
+ YYDPRINTF ((stderr, "Removing dead stacks.\n"));
+ }
+ yystackp->yytops.yysize -= 1;
+ }
else
- {
- yystackp->yytops.yystates[yyj] = yystackp->yytops.yystates[yyi];
- /* In the current implementation, it's unnecessary to copy
- yystackp->yytops.yylookaheadNeeds[yyi] since, after
- yyremoveDeletes returns, the parser immediately either enters
- deterministic operation or shifts a token. However, it doesn't
- hurt, and the code might evolve to need it. */
- yystackp->yytops.yylookaheadNeeds[yyj] =
- yystackp->yytops.yylookaheadNeeds[yyi];
- if (yyj != yyi)
- {
- YYDPRINTF ((stderr, "Rename stack %lu -> %lu.\n",
- (unsigned long int) yyi, (unsigned long int) yyj));
- }
- yyj += 1;
- }
+ {
+ yystackp->yytops.yystates[yyj] = yystackp->yytops.yystates[yyi];
+ /* In the current implementation, it's unnecessary to copy
+ yystackp->yytops.yylookaheadNeeds[yyi] since, after
+ yyremoveDeletes returns, the parser immediately either enters
+ deterministic operation or shifts a token. However, it doesn't
+ hurt, and the code might evolve to need it. */
+ yystackp->yytops.yylookaheadNeeds[yyj] =
+ yystackp->yytops.yylookaheadNeeds[yyi];
+ if (yyj != yyi)
+ {
+ YYDPRINTF ((stderr, "Rename stack %lu -> %lu.\n",
+ (unsigned long int) yyi, (unsigned long int) yyj));
+ }
+ yyj += 1;
+ }
yyi += 1;
}
}
-/** Shift to a new state on stack #K of STACK, corresponding to LR state
- * LRSTATE, at input position POSN, with (resolved) semantic value SVAL. */
+/** Shift to a new state on stack #YYK of *YYSTACKP, corresponding to LR
+ * state YYLRSTATE, at input position YYPOSN, with (resolved) semantic
+ * value *YYVALP and source location *YYLOCP. */
static inline void
yyglrShift (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
- size_t yyposn,
- YYSTYPE* yyvalp]b4_locations_if([, YYLTYPE* yylocp])[)
+ size_t yyposn,
+ YYSTYPE* yyvalp]b4_locations_if([, YYLTYPE* yylocp])[)
{
yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
YY_RESERVE_GLRSTACK (yystackp);
}
-/** Shift stack #K of YYSTACK, to a new state corresponding to LR
+/** Shift stack #YYK of *YYSTACKP, to a new state corresponding to LR
* state YYLRSTATE, at input position YYPOSN, with the (unresolved)
* semantic value of YYRHS under the action for YYRULE. */
static inline void
yyglrShiftDefer (yyGLRStack* yystackp, size_t yyk, yyStateNum yylrState,
- size_t yyposn, yyGLRState* rhs, yyRuleNum yyrule)
+ size_t yyposn, yyGLRState* yyrhs, yyRuleNum yyrule)
{
yyGLRState* yynewState = &yynewGLRStackItem (yystackp, yytrue)->yystate;
yystackp->yytops.yystates[yyk] = yynewState;
/* Invokes YY_RESERVE_GLRSTACK. */
- yyaddDeferredAction (yystackp, yyk, yynewState, rhs, yyrule);
+ yyaddDeferredAction (yystackp, yyk, yynewState, yyrhs, yyrule);
+}
+
+#if !YYDEBUG
+# define YY_REDUCE_PRINT(Args)
+#else
+# define YY_REDUCE_PRINT(Args) \
+do { \
+ if (yydebug) \
+ yy_reduce_print Args; \
+} while (YYID (0))
+
+/*----------------------------------------------------------------------.
+| Report that stack #YYK of *YYSTACKP is going to be reduced by YYRULE. |
+`----------------------------------------------------------------------*/
+
+/*ARGSUSED*/ static inline void
+yy_reduce_print (int yynormal, yyGLRStackItem* yyvsp, size_t yyk,
+ yyRuleNum yyrule]b4_user_formals[)
+{
+ int yynrhs = yyrhsLength (yyrule);]b4_locations_if([
+ int yylow = 1;])[
+ int yyi;
+ YYFPRINTF (stderr, "Reducing stack %lu by rule %d (line %lu):\n",
+ (unsigned long int) yyk, yyrule - 1,
+ (unsigned long int) yyrline[yyrule]);
+ if (! yynormal)
+ yyfillin (yyvsp, 1, -yynrhs);
+ /* The symbols being reduced. */
+ for (yyi = 0; yyi < yynrhs; yyi++)
+ {
+ YYFPRINTF (stderr, " $%d = ", yyi + 1);
+ yy_symbol_print (stderr,
+ yystos[yyvsp[yyi - yynrhs + 1].yystate.yylrState],
+ &yyvsp[yyi - yynrhs + 1].yystate.yysemantics.yysval
+ ]b4_locations_if([, &]b4_rhs_location(yynrhs, yyi + 1))[]dnl
+ b4_user_args[);
+ if (!yyvsp[yyi - yynrhs + 1].yystate.yyresolved)
+ YYFPRINTF (stderr, " (unresolved)");
+ YYFPRINTF (stderr, "\n");
+ }
}
+#endif
-/** Pop the symbols consumed by reduction #RULE from the top of stack
- * #K of STACK, and perform the appropriate semantic action on their
+/** Pop the symbols consumed by reduction #YYRULE from the top of stack
+ * #YYK of *YYSTACKP, and perform the appropriate semantic action on their
* semantic values. Assumes that all ambiguities in semantic values
- * have been previously resolved. Set *VALP to the resulting value,
- * and *LOCP to the computed location (if any). Return value is as
+ * have been previously resolved. Set *YYVALP to the resulting value,
+ * and *YYLOCP to the computed location (if any). Return value is as
* for userAction. */
static inline YYRESULTTAG
yydoAction (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
- YYSTYPE* yyvalp]b4_locuser_formals[)
+ YYSTYPE* yyvalp]b4_locuser_formals[)
{
int yynrhs = yyrhsLength (yyrule);
if (yystackp->yysplitPoint == YY_NULL)
{
/* Standard special case: single stack. */
- yyGLRStackItem* rhs = (yyGLRStackItem*) yystackp->yytops.yystates[yyk];
+ yyGLRStackItem* yyrhs = (yyGLRStackItem*) yystackp->yytops.yystates[yyk];
YYASSERT (yyk == 0);
yystackp->yynextFree -= yynrhs;
yystackp->yyspaceLeft += yynrhs;
yystackp->yytops.yystates[0] = & yystackp->yynextFree[-1].yystate;
- return yyuserAction (yyrule, yynrhs, rhs, yystackp,
- yyvalp]b4_locuser_args[);
+ YY_REDUCE_PRINT ((1, yyrhs, yyk, yyrule]b4_user_args[));
+ return yyuserAction (yyrule, yynrhs, yyrhs, yystackp,
+ yyvalp]b4_locuser_args[);
}
else
{
- /* At present, doAction is never called in nondeterministic
- * mode, so this branch is never taken. It is here in
- * anticipation of a future feature that will allow immediate
- * evaluation of selected actions in nondeterministic mode. */
int yyi;
yyGLRState* yys;
yyGLRStackItem yyrhsVals[YYMAXRHS + YYMAXLEFT + 1];
yys = yyrhsVals[YYMAXRHS + YYMAXLEFT].yystate.yypred
- = yystackp->yytops.yystates[yyk];]b4_locations_if([[
+ = yystackp->yytops.yystates[yyk];]b4_locations_if([[
if (yynrhs == 0)
- /* Set default location. */
- yyrhsVals[YYMAXRHS + YYMAXLEFT - 1].yystate.yyloc = yys->yyloc;]])[
+ /* Set default location. */
+ yyrhsVals[YYMAXRHS + YYMAXLEFT - 1].yystate.yyloc = yys->yyloc;]])[
for (yyi = 0; yyi < yynrhs; yyi += 1)
- {
- yys = yys->yypred;
- YYASSERT (yys);
- }
+ {
+ yys = yys->yypred;
+ YYASSERT (yys);
+ }
yyupdateSplit (yystackp, yys);
yystackp->yytops.yystates[yyk] = yys;
+ YY_REDUCE_PRINT ((0, yyrhsVals + YYMAXRHS + YYMAXLEFT - 1, yyk, yyrule]b4_user_args[));
return yyuserAction (yyrule, yynrhs, yyrhsVals + YYMAXRHS + YYMAXLEFT - 1,
- yystackp, yyvalp]b4_locuser_args[);
- }
-}
-
-#if !YYDEBUG
-# define YY_REDUCE_PRINT(Args)
-#else
-# define YY_REDUCE_PRINT(Args) \
-do { \
- if (yydebug) \
- yy_reduce_print Args; \
-} while (YYID (0))
-
-/*----------------------------------------------------------.
-| Report that the RULE is going to be reduced on stack #K. |
-`----------------------------------------------------------*/
-
-/*ARGSUSED*/ static inline void
-yy_reduce_print (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
- YYSTYPE* yyvalp]b4_locuser_formals[)
-{
- int yynrhs = yyrhsLength (yyrule);
- yybool yynormal __attribute__ ((__unused__)) =
- (yystackp->yysplitPoint == YY_NULL);
- yyGLRStackItem* yyvsp = (yyGLRStackItem*) yystackp->yytops.yystates[yyk];
- int yylow = 1;
- int yyi;
- YYUSE (yyvalp);]b4_locations_if([
- YYUSE (yylocp);])[
-]b4_parse_param_use[]dnl
-[ YYFPRINTF (stderr, "Reducing stack %lu by rule %d (line %lu):\n",
- (unsigned long int) yyk, yyrule - 1,
- (unsigned long int) yyrline[yyrule]);
- /* The symbols being reduced. */
- for (yyi = 0; yyi < yynrhs; yyi++)
- {
- YYFPRINTF (stderr, " $%d = ", yyi + 1);
- yy_symbol_print (stderr, yyrhs[yyprhs[yyrule] + yyi],
- &]b4_rhs_value(yynrhs, yyi + 1)[
- ]b4_locations_if([, &]b4_rhs_location(yynrhs, yyi + 1))[]dnl
- b4_user_args[);
- YYFPRINTF (stderr, "\n");
+ yystackp, yyvalp]b4_locuser_args[);
}
}
-#endif
-/** Pop items off stack #K of STACK according to grammar rule RULE,
+/** Pop items off stack #YYK of *YYSTACKP according to grammar rule YYRULE,
* and push back on the resulting nonterminal symbol. Perform the
- * semantic action associated with RULE and store its value with the
- * newly pushed state, if FORCEEVAL or if STACK is currently
+ * semantic action associated with YYRULE and store its value with the
+ * newly pushed state, if YYFORCEEVAL or if *YYSTACKP is currently
* unambiguous. Otherwise, store the deferred semantic action with
* the new state. If the new state would have an identical input
* position, LR state, and predecessor to an existing state on the stack,
- * it is identified with that existing state, eliminating stack #K from
- * the STACK. In this case, the (necessarily deferred) semantic value is
+ * it is identified with that existing state, eliminating stack #YYK from
+ * *YYSTACKP. In this case, the semantic value is
* added to the options for the existing state's semantic value.
*/
static inline YYRESULTTAG
yyglrReduce (yyGLRStack* yystackp, size_t yyk, yyRuleNum yyrule,
- yybool yyforceEval]b4_user_formals[)
+ yybool yyforceEval]b4_user_formals[)
{
size_t yyposn = yystackp->yytops.yystates[yyk]->yyposn;
if (yyforceEval || yystackp->yysplitPoint == YY_NULL)
{
+ YYRESULTTAG yyflag;
YYSTYPE yysval;]b4_locations_if([
YYLTYPE yyloc;])[
- YY_REDUCE_PRINT ((yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[));
- YYCHK (yydoAction (yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[));
+ yyflag = yydoAction (yystackp, yyk, yyrule, &yysval]b4_locuser_args([&yyloc])[);
+ if (yyflag == yyerr && yystackp->yysplitPoint != YY_NULL)
+ {
+ YYDPRINTF ((stderr, "Parse on stack %lu rejected by rule #%d.\n",
+ (unsigned long int) yyk, yyrule - 1));
+ }
+ if (yyflag != yyok)
+ return yyflag;
YY_SYMBOL_PRINT ("-> $$ =", yyr1[yyrule], &yysval, &yyloc);
yyglrShift (yystackp, yyk,
- yyLRgotoState (yystackp->yytops.yystates[yyk]->yylrState,
- yylhsNonterm (yyrule)),
- yyposn, &yysval]b4_locations_if([, &yyloc])[);
+ yyLRgotoState (yystackp->yytops.yystates[yyk]->yylrState,
+ yylhsNonterm (yyrule)),
+ yyposn, &yysval]b4_locations_if([, &yyloc])[);
}
else
{
yyStateNum yynewLRState;
for (yys = yystackp->yytops.yystates[yyk], yyn = yyrhsLength (yyrule);
- 0 < yyn; yyn -= 1)
- {
- yys = yys->yypred;
- YYASSERT (yys);
- }
+ 0 < yyn; yyn -= 1)
+ {
+ yys = yys->yypred;
+ YYASSERT (yys);
+ }
yyupdateSplit (yystackp, yys);
yynewLRState = yyLRgotoState (yys->yylrState, yylhsNonterm (yyrule));
YYDPRINTF ((stderr,
- "Reduced stack %lu by rule #%d; action deferred. Now in state %d.\n",
- (unsigned long int) yyk, yyrule - 1, yynewLRState));
+ "Reduced stack %lu by rule #%d; action deferred. "
+ "Now in state %d.\n",
+ (unsigned long int) yyk, yyrule - 1, yynewLRState));
for (yyi = 0; yyi < yystackp->yytops.yysize; yyi += 1)
- if (yyi != yyk && yystackp->yytops.yystates[yyi] != YY_NULL)
- {
- yyGLRState* yyp, *yysplit = yystackp->yysplitPoint;
- yyp = yystackp->yytops.yystates[yyi];
- while (yyp != yys && yyp != yysplit && yyp->yyposn >= yyposn)
- {
- if (yyp->yylrState == yynewLRState && yyp->yypred == yys)
- {
- yyaddDeferredAction (yystackp, yyk, yyp, yys0, yyrule);
- yymarkStackDeleted (yystackp, yyk);
- YYDPRINTF ((stderr, "Merging stack %lu into stack %lu.\n",
- (unsigned long int) yyk,
- (unsigned long int) yyi));
- return yyok;
- }
- yyp = yyp->yypred;
- }
- }
+ if (yyi != yyk && yystackp->yytops.yystates[yyi] != YY_NULL)
+ {
+ yyGLRState* yyp, *yysplit = yystackp->yysplitPoint;
+ yyp = yystackp->yytops.yystates[yyi];
+ while (yyp != yys && yyp != yysplit && yyp->yyposn >= yyposn)
+ {
+ if (yyp->yylrState == yynewLRState && yyp->yypred == yys)
+ {
+ yyaddDeferredAction (yystackp, yyk, yyp, yys0, yyrule);
+ yymarkStackDeleted (yystackp, yyk);
+ YYDPRINTF ((stderr, "Merging stack %lu into stack %lu.\n",
+ (unsigned long int) yyk,
+ (unsigned long int) yyi));
+ return yyok;
+ }
+ yyp = yyp->yypred;
+ }
+ }
yystackp->yytops.yystates[yyk] = yys;
yyglrShiftDefer (yystackp, yyk, yynewLRState, yyposn, yys0, yyrule);
}
yynewStates = YY_NULL;
if (yystackp->yytops.yycapacity
- > (YYSIZEMAX / (2 * sizeof yynewStates[0])))
- yyMemoryExhausted (yystackp);
+ > (YYSIZEMAX / (2 * sizeof yynewStates[0])))
+ yyMemoryExhausted (yystackp);
yystackp->yytops.yycapacity *= 2;
yynewStates =
- (yyGLRState**) YYREALLOC (yystackp->yytops.yystates,
- (yystackp->yytops.yycapacity
- * sizeof yynewStates[0]));
+ (yyGLRState**) YYREALLOC (yystackp->yytops.yystates,
+ (yystackp->yytops.yycapacity
+ * sizeof yynewStates[0]));
if (yynewStates == YY_NULL)
- yyMemoryExhausted (yystackp);
+ yyMemoryExhausted (yystackp);
yystackp->yytops.yystates = yynewStates;
yynewLookaheadNeeds =
- (yybool*) YYREALLOC (yystackp->yytops.yylookaheadNeeds,
- (yystackp->yytops.yycapacity
- * sizeof yynewLookaheadNeeds[0]));
+ (yybool*) YYREALLOC (yystackp->yytops.yylookaheadNeeds,
+ (yystackp->yytops.yycapacity
+ * sizeof yynewLookaheadNeeds[0]));
if (yynewLookaheadNeeds == YY_NULL)
- yyMemoryExhausted (yystackp);
+ yyMemoryExhausted (yystackp);
yystackp->yytops.yylookaheadNeeds = yynewLookaheadNeeds;
}
yystackp->yytops.yystates[yystackp->yytops.yysize]
return yystackp->yytops.yysize-1;
}
-/** True iff Y0 and Y1 represent identical options at the top level.
+/** True iff YYY0 and YYY1 represent identical options at the top level.
* That is, they represent the same rule applied to RHS symbols
* that produce the same terminal symbols. */
static yybool
yyGLRState *yys0, *yys1;
int yyn;
for (yys0 = yyy0->yystate, yys1 = yyy1->yystate,
- yyn = yyrhsLength (yyy0->yyrule);
- yyn > 0;
- yys0 = yys0->yypred, yys1 = yys1->yypred, yyn -= 1)
- if (yys0->yyposn != yys1->yyposn)
- return yyfalse;
+ yyn = yyrhsLength (yyy0->yyrule);
+ yyn > 0;
+ yys0 = yys0->yypred, yys1 = yys1->yypred, yyn -= 1)
+ if (yys0->yyposn != yys1->yyposn)
+ return yyfalse;
return yytrue;
}
else
return yyfalse;
}
-/** Assuming identicalOptions (Y0,Y1), destructively merge the
- * alternative semantic values for the RHS-symbols of Y1 and Y0. */
+/** Assuming identicalOptions (YYY0,YYY1), destructively merge the
+ * alternative semantic values for the RHS-symbols of YYY1 and YYY0. */
static void
yymergeOptionSets (yySemanticOption* yyy0, yySemanticOption* yyy1)
{
yys0 = yys0->yypred, yys1 = yys1->yypred, yyn -= 1)
{
if (yys0 == yys1)
- break;
+ break;
else if (yys0->yyresolved)
- {
- yys1->yyresolved = yytrue;
- yys1->yysemantics.yysval = yys0->yysemantics.yysval;
- }
+ {
+ yys1->yyresolved = yytrue;
+ yys1->yysemantics.yysval = yys0->yysemantics.yysval;
+ }
else if (yys1->yyresolved)
- {
- yys0->yyresolved = yytrue;
- yys0->yysemantics.yysval = yys1->yysemantics.yysval;
- }
+ {
+ yys0->yyresolved = yytrue;
+ yys0->yysemantics.yysval = yys1->yysemantics.yysval;
+ }
else
- {
- yySemanticOption** yyz0p;
- yySemanticOption* yyz1;
- yyz0p = &yys0->yysemantics.yyfirstVal;
- yyz1 = yys1->yysemantics.yyfirstVal;
- while (YYID (yytrue))
- {
- if (yyz1 == *yyz0p || yyz1 == YY_NULL)
- break;
- else if (*yyz0p == YY_NULL)
- {
- *yyz0p = yyz1;
- break;
- }
- else if (*yyz0p < yyz1)
- {
- yySemanticOption* yyz = *yyz0p;
- *yyz0p = yyz1;
- yyz1 = yyz1->yynext;
- (*yyz0p)->yynext = yyz;
- }
- yyz0p = &(*yyz0p)->yynext;
- }
- yys1->yysemantics.yyfirstVal = yys0->yysemantics.yyfirstVal;
- }
+ {
+ yySemanticOption** yyz0p;
+ yySemanticOption* yyz1;
+ yyz0p = &yys0->yysemantics.yyfirstVal;
+ yyz1 = yys1->yysemantics.yyfirstVal;
+ while (YYID (yytrue))
+ {
+ if (yyz1 == *yyz0p || yyz1 == YY_NULL)
+ break;
+ else if (*yyz0p == YY_NULL)
+ {
+ *yyz0p = yyz1;
+ break;
+ }
+ else if (*yyz0p < yyz1)
+ {
+ yySemanticOption* yyz = *yyz0p;
+ *yyz0p = yyz1;
+ yyz1 = yyz1->yynext;
+ (*yyz0p)->yynext = yyz;
+ }
+ yyz0p = &(*yyz0p)->yynext;
+ }
+ yys1->yysemantics.yyfirstVal = yys0->yysemantics.yyfirstVal;
+ }
}
}
if (p0 == p1)
{
if (yymerger[r0] == 0 || yymerger[r0] != yymerger[r1])
- return 0;
+ return 0;
else
- return 1;
+ return 1;
}
if (p0 == 0 || p1 == 0)
return 0;
}
static YYRESULTTAG yyresolveValue (yyGLRState* yys,
- yyGLRStack* yystackp]b4_user_formals[);
+ yyGLRStack* yystackp]b4_user_formals[);
-/** Resolve the previous N states starting at and including state S. If result
- * != yyok, some states may have been left unresolved possibly with empty
- * semantic option chains. Regardless of whether result = yyok, each state
- * has been left with consistent data so that yydestroyGLRState can be invoked
- * if necessary. */
+/** Resolve the previous YYN states starting at and including state YYS
+ * on *YYSTACKP. If result != yyok, some states may have been left
+ * unresolved possibly with empty semantic option chains. Regardless
+ * of whether result = yyok, each state has been left with consistent
+ * data so that yydestroyGLRState can be invoked if necessary. */
static YYRESULTTAG
yyresolveStates (yyGLRState* yys, int yyn,
- yyGLRStack* yystackp]b4_user_formals[)
+ yyGLRStack* yystackp]b4_user_formals[)
{
if (0 < yyn)
{
YYASSERT (yys->yypred);
YYCHK (yyresolveStates (yys->yypred, yyn-1, yystackp]b4_user_args[));
if (! yys->yyresolved)
- YYCHK (yyresolveValue (yys, yystackp]b4_user_args[));
+ YYCHK (yyresolveValue (yys, yystackp]b4_user_args[));
}
return yyok;
}
-/** Resolve the states for the RHS of OPT, perform its user action, and return
- * the semantic value and location. Regardless of whether result = yyok, all
- * RHS states have been destroyed (assuming the user action destroys all RHS
+/** Resolve the states for the RHS of YYOPT on *YYSTACKP, perform its
+ * user action, and return the semantic value and location in *YYVALP
+ * and *YYLOCP. Regardless of whether result = yyok, all RHS states
+ * have been destroyed (assuming the user action destroys all RHS
* semantic values if invoked). */
static YYRESULTTAG
yyresolveAction (yySemanticOption* yyopt, yyGLRStack* yystackp,
- YYSTYPE* yyvalp]b4_locuser_formals[)
+ YYSTYPE* yyvalp]b4_locuser_formals[)
{
yyGLRStackItem yyrhsVals[YYMAXRHS + YYMAXLEFT + 1];
int yynrhs;
{
yyGLRState *yys;
for (yys = yyopt->yystate; yynrhs > 0; yys = yys->yypred, yynrhs -= 1)
- yydestroyGLRState ("Cleanup: popping", yys]b4_user_args[);
+ yydestroyGLRState ("Cleanup: popping", yys]b4_user_args[);
return yyflag;
}
yylval = yyopt->yyval;]b4_locations_if([
yylloc = yyopt->yyloc;])[
yyflag = yyuserAction (yyopt->yyrule, yynrhs,
- yyrhsVals + YYMAXRHS + YYMAXLEFT - 1,
- yystackp, yyvalp]b4_locuser_args[);
+ yyrhsVals + YYMAXRHS + YYMAXLEFT - 1,
+ yystackp, yyvalp]b4_locuser_args[);
yychar = yychar_current;
yylval = yylval_current;]b4_locations_if([
yylloc = yylloc_current;])[
if (yyx->yystate->yyposn < yys->yyposn + 1)
YYFPRINTF (stderr, "%*s%s -> <Rule %d, empty>\n",
- yyindent, "", yytokenName (yylhsNonterm (yyx->yyrule)),
- yyx->yyrule - 1);
+ yyindent, "", yytokenName (yylhsNonterm (yyx->yyrule)),
+ yyx->yyrule - 1);
else
YYFPRINTF (stderr, "%*s%s -> <Rule %d, tokens %lu .. %lu>\n",
- yyindent, "", yytokenName (yylhsNonterm (yyx->yyrule)),
- yyx->yyrule - 1, (unsigned long int) (yys->yyposn + 1),
- (unsigned long int) yyx->yystate->yyposn);
+ yyindent, "", yytokenName (yylhsNonterm (yyx->yyrule)),
+ yyx->yyrule - 1, (unsigned long int) (yys->yyposn + 1),
+ (unsigned long int) yyx->yystate->yyposn);
for (yyi = 1; yyi <= yynrhs; yyi += 1)
{
if (yystates[yyi]->yyresolved)
- {
- if (yystates[yyi-1]->yyposn+1 > yystates[yyi]->yyposn)
- YYFPRINTF (stderr, "%*s%s <empty>\n", yyindent+2, "",
- yytokenName (yyrhs[yyprhs[yyx->yyrule]+yyi-1]));
- else
- YYFPRINTF (stderr, "%*s%s <tokens %lu .. %lu>\n", yyindent+2, "",
- yytokenName (yyrhs[yyprhs[yyx->yyrule]+yyi-1]),
- (unsigned long int) (yystates[yyi - 1]->yyposn + 1),
- (unsigned long int) yystates[yyi]->yyposn);
- }
+ {
+ if (yystates[yyi-1]->yyposn+1 > yystates[yyi]->yyposn)
+ YYFPRINTF (stderr, "%*s%s <empty>\n", yyindent+2, "",
+ yytokenName (yystos[yystates[yyi]->yylrState]));
+ else
+ YYFPRINTF (stderr, "%*s%s <tokens %lu .. %lu>\n", yyindent+2, "",
+ yytokenName (yystos[yystates[yyi]->yylrState]),
+ (unsigned long int) (yystates[yyi-1]->yyposn + 1),
+ (unsigned long int) yystates[yyi]->yyposn);
+ }
else
- yyreportTree (yystates[yyi]->yysemantics.yyfirstVal, yyindent+2);
+ yyreportTree (yystates[yyi]->yysemantics.yyfirstVal, yyindent+2);
}
}
#endif
/*ARGSUSED*/ static YYRESULTTAG
yyreportAmbiguity (yySemanticOption* yyx0,
- yySemanticOption* yyx1]b4_pure_formals[)
+ yySemanticOption* yyx1]b4_pure_formals[)
{
YYUSE (yyx0);
YYUSE (yyx1);
return yyabort;
}]b4_locations_if([[
-/** Starting at and including state S1, resolve the location for each of the
- * previous N1 states that is unresolved. The first semantic option of a state
- * is always chosen. */
+/** Resolve the locations for each of the YYN1 states in *YYSTACKP,
+ * ending at YYS1. Has no effect on previously resolved states.
+ * The first semantic option of a state is always chosen. */
static void
yyresolveLocations (yyGLRState* yys1, int yyn1,
- yyGLRStack *yystackp]b4_user_formals[)
+ yyGLRStack *yystackp]b4_user_formals[)
{
if (0 < yyn1)
{
yyresolveLocations (yys1->yypred, yyn1 - 1, yystackp]b4_user_args[);
if (!yys1->yyresolved)
- {
- yySemanticOption *yyoption;
- yyGLRStackItem yyrhsloc[1 + YYMAXRHS];
- int yynrhs;
- int yychar_current;
- YYSTYPE yylval_current;
- YYLTYPE yylloc_current;
- yyoption = yys1->yysemantics.yyfirstVal;
- YYASSERT (yyoption != YY_NULL);
- yynrhs = yyrhsLength (yyoption->yyrule);
- if (yynrhs > 0)
- {
- yyGLRState *yys;
- int yyn;
- yyresolveLocations (yyoption->yystate, yynrhs,
- yystackp]b4_user_args[);
- for (yys = yyoption->yystate, yyn = yynrhs;
- yyn > 0;
- yys = yys->yypred, yyn -= 1)
- yyrhsloc[yyn].yystate.yyloc = yys->yyloc;
- }
- else
- {
- /* Both yyresolveAction and yyresolveLocations traverse the GSS
- in reverse rightmost order. It is only necessary to invoke
- yyresolveLocations on a subforest for which yyresolveAction
- would have been invoked next had an ambiguity not been
- detected. Thus the location of the previous state (but not
- necessarily the previous state itself) is guaranteed to be
- resolved already. */
- yyGLRState *yyprevious = yyoption->yystate;
- yyrhsloc[0].yystate.yyloc = yyprevious->yyloc;
- }
- yychar_current = yychar;
- yylval_current = yylval;
- yylloc_current = yylloc;
- yychar = yyoption->yyrawchar;
- yylval = yyoption->yyval;
- yylloc = yyoption->yyloc;
- YYLLOC_DEFAULT ((yys1->yyloc), yyrhsloc, yynrhs);
- yychar = yychar_current;
- yylval = yylval_current;
- yylloc = yylloc_current;
- }
+ {
+ yySemanticOption *yyoption;
+ yyGLRStackItem yyrhsloc[1 + YYMAXRHS];
+ int yynrhs;
+ int yychar_current;
+ YYSTYPE yylval_current;
+ YYLTYPE yylloc_current;
+ yyoption = yys1->yysemantics.yyfirstVal;
+ YYASSERT (yyoption != YY_NULL);
+ yynrhs = yyrhsLength (yyoption->yyrule);
+ if (yynrhs > 0)
+ {
+ yyGLRState *yys;
+ int yyn;
+ yyresolveLocations (yyoption->yystate, yynrhs,
+ yystackp]b4_user_args[);
+ for (yys = yyoption->yystate, yyn = yynrhs;
+ yyn > 0;
+ yys = yys->yypred, yyn -= 1)
+ yyrhsloc[yyn].yystate.yyloc = yys->yyloc;
+ }
+ else
+ {
+ /* Both yyresolveAction and yyresolveLocations traverse the GSS
+ in reverse rightmost order. It is only necessary to invoke
+ yyresolveLocations on a subforest for which yyresolveAction
+ would have been invoked next had an ambiguity not been
+ detected. Thus the location of the previous state (but not
+ necessarily the previous state itself) is guaranteed to be
+ resolved already. */
+ yyGLRState *yyprevious = yyoption->yystate;
+ yyrhsloc[0].yystate.yyloc = yyprevious->yyloc;
+ }
+ yychar_current = yychar;
+ yylval_current = yylval;
+ yylloc_current = yylloc;
+ yychar = yyoption->yyrawchar;
+ yylval = yyoption->yyval;
+ yylloc = yyoption->yyloc;
+ YYLLOC_DEFAULT ((yys1->yyloc), yyrhsloc, yynrhs);
+ yychar = yychar_current;
+ yylval = yylval_current;
+ yylloc = yylloc_current;
+ }
}
}]])[
-/** Resolve the ambiguity represented in state S, perform the indicated
- * actions, and set the semantic value of S. If result != yyok, the chain of
- * semantic options in S has been cleared instead or it has been left
- * unmodified except that redundant options may have been removed. Regardless
- * of whether result = yyok, S has been left with consistent data so that
+/** Resolve the ambiguity represented in state YYS in *YYSTACKP,
+ * perform the indicated actions, and set the semantic value of YYS.
+ * If result != yyok, the chain of semantic options in YYS has been
+ * cleared instead or it has been left unmodified except that
+ * redundant options may have been removed. Regardless of whether
+ * result = yyok, YYS has been left with consistent data so that
* yydestroyGLRState can be invoked if necessary. */
static YYRESULTTAG
yyresolveValue (yyGLRState* yys, yyGLRStack* yystackp]b4_user_formals[)
yySemanticOption* yyp = *yypp;
if (yyidenticalOptions (yybest, yyp))
- {
- yymergeOptionSets (yybest, yyp);
- *yypp = yyp->yynext;
- }
+ {
+ yymergeOptionSets (yybest, yyp);
+ *yypp = yyp->yynext;
+ }
else
- {
- switch (yypreference (yybest, yyp))
- {
- case 0:]b4_locations_if([[
- yyresolveLocations (yys, 1, yystackp]b4_user_args[);]])[
- return yyreportAmbiguity (yybest, yyp]b4_pure_args[);
- break;
- case 1:
- yymerge = yytrue;
- break;
- case 2:
- break;
- case 3:
- yybest = yyp;
- yymerge = yyfalse;
- break;
- default:
- /* This cannot happen so it is not worth a YYASSERT (yyfalse),
- but some compilers complain if the default case is
- omitted. */
- break;
- }
- yypp = &yyp->yynext;
- }
+ {
+ switch (yypreference (yybest, yyp))
+ {
+ case 0:]b4_locations_if([[
+ yyresolveLocations (yys, 1, yystackp]b4_user_args[);]])[
+ return yyreportAmbiguity (yybest, yyp]b4_pure_args[);
+ break;
+ case 1:
+ yymerge = yytrue;
+ break;
+ case 2:
+ break;
+ case 3:
+ yybest = yyp;
+ yymerge = yyfalse;
+ break;
+ default:
+ /* This cannot happen so it is not worth a YYASSERT (yyfalse),
+ but some compilers complain if the default case is
+ omitted. */
+ break;
+ }
+ yypp = &yyp->yynext;
+ }
}
if (yymerge)
int yyprec = yydprec[yybest->yyrule];
yyflag = yyresolveAction (yybest, yystackp, &yysval]b4_locuser_args[);
if (yyflag == yyok)
- for (yyp = yybest->yynext; yyp != YY_NULL; yyp = yyp->yynext)
- {
- if (yyprec == yydprec[yyp->yyrule])
- {
- YYSTYPE yysval_other;]b4_locations_if([
+ for (yyp = yybest->yynext; yyp != YY_NULL; yyp = yyp->yynext)
+ {
+ if (yyprec == yydprec[yyp->yyrule])
+ {
+ YYSTYPE yysval_other;]b4_locations_if([
YYLTYPE yydummy;])[
yyflag = yyresolveAction (yyp, yystackp, &yysval_other]b4_locuser_args([&yydummy])[);
- if (yyflag != yyok)
- {
- yydestruct ("Cleanup: discarding incompletely merged value for",
- yystos[yys->yylrState],
- &yysval]b4_locuser_args[);
- break;
- }
- yyuserMerge (yymerger[yyp->yyrule], &yysval, &yysval_other);
- }
- }
+ if (yyflag != yyok)
+ {
+ yydestruct ("Cleanup: discarding incompletely merged value for",
+ yystos[yys->yylrState],
+ &yysval]b4_locuser_args[);
+ break;
+ }
+ yyuserMerge (yymerger[yyp->yyrule], &yysval, &yysval_other);
+ }
+ }
}
else
yyflag = yyresolveAction (yybest, yystackp, &yysval]b4_locuser_args([yylocp])[);
int yyn;
for (yyn = 0, yys = yystackp->yytops.yystates[0];
- yys != yystackp->yysplitPoint;
- yys = yys->yypred, yyn += 1)
- continue;
+ yys != yystackp->yysplitPoint;
+ yys = yys->yypred, yyn += 1)
+ continue;
YYCHK (yyresolveStates (yystackp->yytops.yystates[0], yyn, yystackp
- ]b4_user_args[));
+ ]b4_user_args[));
}
return yyok;
}
static YYRESULTTAG
yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
- size_t yyposn]b4_pure_formals[)
+ size_t yyposn]b4_pure_formals[)
{
- int yyaction;
- const short int* yyconflicts;
- yyRuleNum yyrule;
-
while (yystackp->yytops.yystates[yyk] != YY_NULL)
{
yyStateNum yystate = yystackp->yytops.yystates[yyk]->yylrState;
YYDPRINTF ((stderr, "Stack %lu Entering state %d\n",
- (unsigned long int) yyk, yystate));
+ (unsigned long int) yyk, yystate));
YYASSERT (yystate != YYFINAL);
if (yyisDefaultedState (yystate))
- {
- yyrule = yydefaultAction (yystate);
- if (yyrule == 0)
- {
- YYDPRINTF ((stderr, "Stack %lu dies.\n",
- (unsigned long int) yyk));
- yymarkStackDeleted (yystackp, yyk);
- return yyok;
- }
- YYCHK (yyglrReduce (yystackp, yyk, yyrule, yyfalse]b4_user_args[));
- }
+ {
+ YYRESULTTAG yyflag;
+ yyRuleNum yyrule = yydefaultAction (yystate);
+ if (yyrule == 0)
+ {
+ YYDPRINTF ((stderr, "Stack %lu dies.\n",
+ (unsigned long int) yyk));
+ yymarkStackDeleted (yystackp, yyk);
+ return yyok;
+ }
+ yyflag = yyglrReduce (yystackp, yyk, yyrule, yyimmediate[yyrule]]b4_user_args[);
+ if (yyflag == yyerr)
+ {
+ YYDPRINTF ((stderr,
+ "Stack %lu dies "
+ "(predicate failure or explicit user error).\n",
+ (unsigned long int) yyk));
+ yymarkStackDeleted (yystackp, yyk);
+ return yyok;
+ }
+ if (yyflag != yyok)
+ return yyflag;
+ }
else
- {
- yySymbol yytoken;
- yystackp->yytops.yylookaheadNeeds[yyk] = yytrue;
- if (yychar == YYEMPTY)
- {
- YYDPRINTF ((stderr, "Reading a token: "));
- yychar = YYLEX;
- }
-
- if (yychar <= YYEOF)
- {
- yychar = yytoken = YYEOF;
- YYDPRINTF ((stderr, "Now at end of input.\n"));
- }
- else
- {
- yytoken = YYTRANSLATE (yychar);
- YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
- }
-
- yygetLRActions (yystate, yytoken, &yyaction, &yyconflicts);
-
- while (*yyconflicts != 0)
- {
- size_t yynewStack = yysplitStack (yystackp, yyk);
- YYDPRINTF ((stderr, "Splitting off stack %lu from %lu.\n",
- (unsigned long int) yynewStack,
- (unsigned long int) yyk));
- YYCHK (yyglrReduce (yystackp, yynewStack,
- *yyconflicts, yyfalse]b4_user_args[));
- YYCHK (yyprocessOneStack (yystackp, yynewStack,
- yyposn]b4_pure_args[));
- yyconflicts += 1;
- }
-
- if (yyisShiftAction (yyaction))
- break;
- else if (yyisErrorAction (yyaction))
- {
- YYDPRINTF ((stderr, "Stack %lu dies.\n",
- (unsigned long int) yyk));
- yymarkStackDeleted (yystackp, yyk);
- break;
- }
- else
- YYCHK (yyglrReduce (yystackp, yyk, -yyaction,
- yyfalse]b4_user_args[));
- }
+ {
+ yySymbol yytoken;
+ int yyaction;
+ const short int* yyconflicts;
+
+ yystackp->yytops.yylookaheadNeeds[yyk] = yytrue;
+ if (yychar == YYEMPTY)
+ {
+ YYDPRINTF ((stderr, "Reading a token: "));
+ yychar = YYLEX;
+ }
+
+ if (yychar <= YYEOF)
+ {
+ yychar = yytoken = YYEOF;
+ YYDPRINTF ((stderr, "Now at end of input.\n"));
+ }
+ else
+ {
+ yytoken = YYTRANSLATE (yychar);
+ YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
+ }
+
+ yygetLRActions (yystate, yytoken, &yyaction, &yyconflicts);
+
+ while (*yyconflicts != 0)
+ {
+ YYRESULTTAG yyflag;
+ size_t yynewStack = yysplitStack (yystackp, yyk);
+ YYDPRINTF ((stderr, "Splitting off stack %lu from %lu.\n",
+ (unsigned long int) yynewStack,
+ (unsigned long int) yyk));
+ yyflag = yyglrReduce (yystackp, yynewStack,
+ *yyconflicts,
+ yyimmediate[*yyconflicts]]b4_user_args[);
+ if (yyflag == yyok)
+ YYCHK (yyprocessOneStack (yystackp, yynewStack,
+ yyposn]b4_pure_args[));
+ else if (yyflag == yyerr)
+ {
+ YYDPRINTF ((stderr, "Stack %lu dies.\n",
+ (unsigned long int) yynewStack));
+ yymarkStackDeleted (yystackp, yynewStack);
+ }
+ else
+ return yyflag;
+ yyconflicts += 1;
+ }
+
+ if (yyisShiftAction (yyaction))
+ break;
+ else if (yyisErrorAction (yyaction))
+ {
+ YYDPRINTF ((stderr, "Stack %lu dies.\n",
+ (unsigned long int) yyk));
+ yymarkStackDeleted (yystackp, yyk);
+ break;
+ }
+ else
+ {
+ YYRESULTTAG yyflag = yyglrReduce (yystackp, yyk, -yyaction,
+ yyimmediate[-yyaction]]b4_user_args[);
+ if (yyflag == yyerr)
+ {
+ YYDPRINTF ((stderr,
+ "Stack %lu dies "
+ "(predicate failure or explicit user error).\n",
+ (unsigned long int) yyk));
+ yymarkStackDeleted (yystackp, yyk);
+ break;
+ }
+ else if (yyflag != yyok)
+ return yyflag;
+ }
+ }
}
return yyok;
}
reductions. Skip tokens until we can proceed. */
while (YYID (yytrue))
{
- yySymbol yytoken;
- if (yychar == YYEOF)
- yyFail (yystackp][]b4_lpure_args[, YY_NULL);
- if (yychar != YYEMPTY)
- {]b4_locations_if([[
- /* We throw away the lookahead, but the error range
- of the shifted error token must take it into account. */
- yyGLRState *yys = yystackp->yytops.yystates[0];
- yyGLRStackItem yyerror_range[3];
- yyerror_range[1].yystate.yyloc = yys->yyloc;
- yyerror_range[2].yystate.yyloc = yylloc;
- YYLLOC_DEFAULT ((yys->yyloc), yyerror_range, 2);]])[
- yytoken = YYTRANSLATE (yychar);
- yydestruct ("Error: discarding",
- yytoken, &yylval]b4_locuser_args([&yylloc])[);
- }
- YYDPRINTF ((stderr, "Reading a token: "));
- yychar = YYLEX;
- if (yychar <= YYEOF)
- {
- yychar = yytoken = YYEOF;
- YYDPRINTF ((stderr, "Now at end of input.\n"));
- }
- else
- {
- yytoken = YYTRANSLATE (yychar);
- YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
- }
- yyj = yypact[yystackp->yytops.yystates[0]->yylrState];
- if (yypact_value_is_default (yyj))
- return;
- yyj += yytoken;
- if (yyj < 0 || YYLAST < yyj || yycheck[yyj] != yytoken)
- {
- if (yydefact[yystackp->yytops.yystates[0]->yylrState] != 0)
- return;
- }
- else if (! yytable_value_is_error (yytable[yyj]))
- return;
+ yySymbol yytoken;
+ if (yychar == YYEOF)
+ yyFail (yystackp][]b4_lpure_args[, YY_NULL);
+ if (yychar != YYEMPTY)
+ {]b4_locations_if([[
+ /* We throw away the lookahead, but the error range
+ of the shifted error token must take it into account. */
+ yyGLRState *yys = yystackp->yytops.yystates[0];
+ yyGLRStackItem yyerror_range[3];
+ yyerror_range[1].yystate.yyloc = yys->yyloc;
+ yyerror_range[2].yystate.yyloc = yylloc;
+ YYLLOC_DEFAULT ((yys->yyloc), yyerror_range, 2);]])[
+ yytoken = YYTRANSLATE (yychar);
+ yydestruct ("Error: discarding",
+ yytoken, &yylval]b4_locuser_args([&yylloc])[);
+ }
+ YYDPRINTF ((stderr, "Reading a token: "));
+ yychar = YYLEX;
+ if (yychar <= YYEOF)
+ {
+ yychar = yytoken = YYEOF;
+ YYDPRINTF ((stderr, "Now at end of input.\n"));
+ }
+ else
+ {
+ yytoken = YYTRANSLATE (yychar);
+ YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
+ }
+ yyj = yypact[yystackp->yytops.yystates[0]->yylrState];
+ if (yypact_value_is_default (yyj))
+ return;
+ yyj += yytoken;
+ if (yyj < 0 || YYLAST < yyj || yycheck[yyj] != yytoken)
+ {
+ if (yydefact[yystackp->yytops.yystates[0]->yylrState] != 0)
+ return;
+ }
+ else if (! yytable_value_is_error (yytable[yyj]))
+ return;
}
/* Reduce to one stack. */
yyGLRState *yys = yystackp->yytops.yystates[0];
yyj = yypact[yys->yylrState];
if (! yypact_value_is_default (yyj))
- {
- yyj += YYTERROR;
- if (0 <= yyj && yyj <= YYLAST && yycheck[yyj] == YYTERROR
- && yyisShiftAction (yytable[yyj]))
- {
- /* Shift the error token. */]b4_locations_if([[
- /* First adjust its location.*/
+ {
+ yyj += YYTERROR;
+ if (0 <= yyj && yyj <= YYLAST && yycheck[yyj] == YYTERROR
+ && yyisShiftAction (yytable[yyj]))
+ {
+ /* Shift the error token. */]b4_locations_if([[
+ /* First adjust its location.*/
YYLTYPE yyerrloc;
- yystackp->yyerror_range[2].yystate.yyloc = yylloc;
- YYLLOC_DEFAULT (yyerrloc, (yystackp->yyerror_range), 2);]])[
- YY_SYMBOL_PRINT ("Shifting", yystos[yytable[yyj]],
- &yylval, &yyerrloc);
- yyglrShift (yystackp, 0, yytable[yyj],
- yys->yyposn, &yylval]b4_locations_if([, &yyerrloc])[);
- yys = yystackp->yytops.yystates[0];
- break;
- }
- }]b4_locations_if([[
+ yystackp->yyerror_range[2].yystate.yyloc = yylloc;
+ YYLLOC_DEFAULT (yyerrloc, (yystackp->yyerror_range), 2);]])[
+ YY_SYMBOL_PRINT ("Shifting", yystos[yytable[yyj]],
+ &yylval, &yyerrloc);
+ yyglrShift (yystackp, 0, yytable[yyj],
+ yys->yyposn, &yylval]b4_locations_if([, &yyerrloc])[);
+ yys = yystackp->yytops.yystates[0];
+ break;
+ }
+ }]b4_locations_if([[
yystackp->yyerror_range[1].yystate.yyloc = yys->yyloc;]])[
if (yys->yypred != YY_NULL)
- yydestroyGLRState ("Error: popping", yys]b4_user_args[);
+ yydestroyGLRState ("Error: popping", yys]b4_user_args[);
yystackp->yytops.yystates[0] = yys->yypred;
yystackp->yynextFree -= 1;
yystackp->yyspaceLeft += 1;
yyFail (yystackp][]b4_lpure_args[, YY_NULL);
}
-#define YYCHK1(YYE) \
- do { \
- switch (YYE) { \
- case yyok: \
- break; \
- case yyabort: \
- goto yyabortlab; \
- case yyaccept: \
- goto yyacceptlab; \
- case yyerr: \
- goto yyuser_error; \
- default: \
- goto yybuglab; \
- } \
+#define YYCHK1(YYE) \
+ do { \
+ switch (YYE) { \
+ case yyok: \
+ break; \
+ case yyabort: \
+ goto yyabortlab; \
+ case yyaccept: \
+ goto yyacceptlab; \
+ case yyerr: \
+ goto yyuser_error; \
+ default: \
+ goto yybuglab; \
+ } \
} while (YYID (0))
-
/*----------.
| yyparse. |
`----------*/
while (YYID (yytrue))
{
/* For efficiency, we have two loops, the first of which is
- specialized to deterministic operation (single stack, no
- potential ambiguity). */
+ specialized to deterministic operation (single stack, no
+ potential ambiguity). */
/* Standard mode */
while (YYID (yytrue))
- {
- yyRuleNum yyrule;
- int yyaction;
- const short int* yyconflicts;
-
- yyStateNum yystate = yystack.yytops.yystates[0]->yylrState;
- YYDPRINTF ((stderr, "Entering state %d\n", yystate));
- if (yystate == YYFINAL)
- goto yyacceptlab;
- if (yyisDefaultedState (yystate))
- {
- yyrule = yydefaultAction (yystate);
- if (yyrule == 0)
- {
-]b4_locations_if([[ yystack.yyerror_range[1].yystate.yyloc = yylloc;]])[
- yyreportSyntaxError (&yystack]b4_user_args[);
- goto yyuser_error;
- }
- YYCHK1 (yyglrReduce (&yystack, 0, yyrule, yytrue]b4_user_args[));
- }
- else
- {
- yySymbol yytoken;
- if (yychar == YYEMPTY)
- {
- YYDPRINTF ((stderr, "Reading a token: "));
- yychar = YYLEX;
- }
-
- if (yychar <= YYEOF)
- {
- yychar = yytoken = YYEOF;
- YYDPRINTF ((stderr, "Now at end of input.\n"));
- }
- else
- {
- yytoken = YYTRANSLATE (yychar);
- YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
- }
-
- yygetLRActions (yystate, yytoken, &yyaction, &yyconflicts);
- if (*yyconflicts != 0)
- break;
- if (yyisShiftAction (yyaction))
- {
- YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);
- yychar = YYEMPTY;
- yyposn += 1;
- yyglrShift (&yystack, 0, yyaction, yyposn, &yylval]b4_locations_if([, &yylloc])[);
- if (0 < yystack.yyerrState)
- yystack.yyerrState -= 1;
- }
- else if (yyisErrorAction (yyaction))
- {
-]b4_locations_if([[ yystack.yyerror_range[1].yystate.yyloc = yylloc;]])[
- yyreportSyntaxError (&yystack]b4_user_args[);
- goto yyuser_error;
- }
- else
- YYCHK1 (yyglrReduce (&yystack, 0, -yyaction, yytrue]b4_user_args[));
- }
- }
+ {
+ yyRuleNum yyrule;
+ int yyaction;
+ const short int* yyconflicts;
+
+ yyStateNum yystate = yystack.yytops.yystates[0]->yylrState;
+ YYDPRINTF ((stderr, "Entering state %d\n", yystate));
+ if (yystate == YYFINAL)
+ goto yyacceptlab;
+ if (yyisDefaultedState (yystate))
+ {
+ yyrule = yydefaultAction (yystate);
+ if (yyrule == 0)
+ {
+]b4_locations_if([[ yystack.yyerror_range[1].yystate.yyloc = yylloc;]])[
+ yyreportSyntaxError (&yystack]b4_user_args[);
+ goto yyuser_error;
+ }
+ YYCHK1 (yyglrReduce (&yystack, 0, yyrule, yytrue]b4_user_args[));
+ }
+ else
+ {
+ yySymbol yytoken;
+ if (yychar == YYEMPTY)
+ {
+ YYDPRINTF ((stderr, "Reading a token: "));
+ yychar = YYLEX;
+ }
+
+ if (yychar <= YYEOF)
+ {
+ yychar = yytoken = YYEOF;
+ YYDPRINTF ((stderr, "Now at end of input.\n"));
+ }
+ else
+ {
+ yytoken = YYTRANSLATE (yychar);
+ YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
+ }
+
+ yygetLRActions (yystate, yytoken, &yyaction, &yyconflicts);
+ if (*yyconflicts != 0)
+ break;
+ if (yyisShiftAction (yyaction))
+ {
+ YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);
+ yychar = YYEMPTY;
+ yyposn += 1;
+ yyglrShift (&yystack, 0, yyaction, yyposn, &yylval]b4_locations_if([, &yylloc])[);
+ if (0 < yystack.yyerrState)
+ yystack.yyerrState -= 1;
+ }
+ else if (yyisErrorAction (yyaction))
+ {
+]b4_locations_if([[ yystack.yyerror_range[1].yystate.yyloc = yylloc;]])[
+ yyreportSyntaxError (&yystack]b4_user_args[);
+ goto yyuser_error;
+ }
+ else
+ YYCHK1 (yyglrReduce (&yystack, 0, -yyaction, yytrue]b4_user_args[));
+ }
+ }
while (YYID (yytrue))
- {
- yySymbol yytoken_to_shift;
- size_t yys;
-
- for (yys = 0; yys < yystack.yytops.yysize; yys += 1)
- yystackp->yytops.yylookaheadNeeds[yys] = yychar != YYEMPTY;
-
- /* yyprocessOneStack returns one of three things:
-
- - An error flag. If the caller is yyprocessOneStack, it
- immediately returns as well. When the caller is finally
- yyparse, it jumps to an error label via YYCHK1.
-
- - yyok, but yyprocessOneStack has invoked yymarkStackDeleted
- (&yystack, yys), which sets the top state of yys to NULL. Thus,
- yyparse's following invocation of yyremoveDeletes will remove
- the stack.
-
- - yyok, when ready to shift a token.
-
- Except in the first case, yyparse will invoke yyremoveDeletes and
- then shift the next token onto all remaining stacks. This
- synchronization of the shift (that is, after all preceding
- reductions on all stacks) helps prevent double destructor calls
- on yylval in the event of memory exhaustion. */
-
- for (yys = 0; yys < yystack.yytops.yysize; yys += 1)
- YYCHK1 (yyprocessOneStack (&yystack, yys, yyposn]b4_lpure_args[));
- yyremoveDeletes (&yystack);
- if (yystack.yytops.yysize == 0)
- {
- yyundeleteLastStack (&yystack);
- if (yystack.yytops.yysize == 0)
- yyFail (&yystack][]b4_lpure_args[, YY_("syntax error"));
- YYCHK1 (yyresolveStack (&yystack]b4_user_args[));
- YYDPRINTF ((stderr, "Returning to deterministic operation.\n"));
-]b4_locations_if([[ yystack.yyerror_range[1].yystate.yyloc = yylloc;]])[
- yyreportSyntaxError (&yystack]b4_user_args[);
- goto yyuser_error;
- }
-
- /* If any yyglrShift call fails, it will fail after shifting. Thus,
- a copy of yylval will already be on stack 0 in the event of a
- failure in the following loop. Thus, yychar is set to YYEMPTY
- before the loop to make sure the user destructor for yylval isn't
- called twice. */
- yytoken_to_shift = YYTRANSLATE (yychar);
- yychar = YYEMPTY;
- yyposn += 1;
- for (yys = 0; yys < yystack.yytops.yysize; yys += 1)
- {
- int yyaction;
- const short int* yyconflicts;
- yyStateNum yystate = yystack.yytops.yystates[yys]->yylrState;
- yygetLRActions (yystate, yytoken_to_shift, &yyaction,
- &yyconflicts);
- /* Note that yyconflicts were handled by yyprocessOneStack. */
- YYDPRINTF ((stderr, "On stack %lu, ", (unsigned long int) yys));
- YY_SYMBOL_PRINT ("shifting", yytoken_to_shift, &yylval, &yylloc);
- yyglrShift (&yystack, yys, yyaction, yyposn,
- &yylval]b4_locations_if([, &yylloc])[);
- YYDPRINTF ((stderr, "Stack %lu now in state #%d\n",
- (unsigned long int) yys,
- yystack.yytops.yystates[yys]->yylrState));
- }
-
- if (yystack.yytops.yysize == 1)
- {
- YYCHK1 (yyresolveStack (&yystack]b4_user_args[));
- YYDPRINTF ((stderr, "Returning to deterministic operation.\n"));
- yycompressStack (&yystack);
- break;
- }
- }
+ {
+ yySymbol yytoken_to_shift;
+ size_t yys;
+
+ for (yys = 0; yys < yystack.yytops.yysize; yys += 1)
+ yystackp->yytops.yylookaheadNeeds[yys] = yychar != YYEMPTY;
+
+ /* yyprocessOneStack returns one of three things:
+
+ - An error flag. If the caller is yyprocessOneStack, it
+ immediately returns as well. When the caller is finally
+ yyparse, it jumps to an error label via YYCHK1.
+
+ - yyok, but yyprocessOneStack has invoked yymarkStackDeleted
+ (&yystack, yys), which sets the top state of yys to NULL. Thus,
+ yyparse's following invocation of yyremoveDeletes will remove
+ the stack.
+
+ - yyok, when ready to shift a token.
+
+ Except in the first case, yyparse will invoke yyremoveDeletes and
+ then shift the next token onto all remaining stacks. This
+ synchronization of the shift (that is, after all preceding
+ reductions on all stacks) helps prevent double destructor calls
+ on yylval in the event of memory exhaustion. */
+
+ for (yys = 0; yys < yystack.yytops.yysize; yys += 1)
+ YYCHK1 (yyprocessOneStack (&yystack, yys, yyposn]b4_lpure_args[));
+ yyremoveDeletes (&yystack);
+ if (yystack.yytops.yysize == 0)
+ {
+ yyundeleteLastStack (&yystack);
+ if (yystack.yytops.yysize == 0)
+ yyFail (&yystack][]b4_lpure_args[, YY_("syntax error"));
+ YYCHK1 (yyresolveStack (&yystack]b4_user_args[));
+ YYDPRINTF ((stderr, "Returning to deterministic operation.\n"));
+]b4_locations_if([[ yystack.yyerror_range[1].yystate.yyloc = yylloc;]])[
+ yyreportSyntaxError (&yystack]b4_user_args[);
+ goto yyuser_error;
+ }
+
+ /* If any yyglrShift call fails, it will fail after shifting. Thus,
+ a copy of yylval will already be on stack 0 in the event of a
+ failure in the following loop. Thus, yychar is set to YYEMPTY
+ before the loop to make sure the user destructor for yylval isn't
+ called twice. */
+ yytoken_to_shift = YYTRANSLATE (yychar);
+ yychar = YYEMPTY;
+ yyposn += 1;
+ for (yys = 0; yys < yystack.yytops.yysize; yys += 1)
+ {
+ int yyaction;
+ const short int* yyconflicts;
+ yyStateNum yystate = yystack.yytops.yystates[yys]->yylrState;
+ yygetLRActions (yystate, yytoken_to_shift, &yyaction,
+ &yyconflicts);
+ /* Note that yyconflicts were handled by yyprocessOneStack. */
+ YYDPRINTF ((stderr, "On stack %lu, ", (unsigned long int) yys));
+ YY_SYMBOL_PRINT ("shifting", yytoken_to_shift, &yylval, &yylloc);
+ yyglrShift (&yystack, yys, yyaction, yyposn,
+ &yylval]b4_locations_if([, &yylloc])[);
+ YYDPRINTF ((stderr, "Stack %lu now in state #%d\n",
+ (unsigned long int) yys,
+ yystack.yytops.yystates[yys]->yylrState));
+ }
+
+ if (yystack.yytops.yysize == 1)
+ {
+ YYCHK1 (yyresolveStack (&yystack]b4_user_args[));
+ YYDPRINTF ((stderr, "Returning to deterministic operation.\n"));
+ yycompressStack (&yystack);
+ break;
+ }
+ }
continue;
yyuser_error:
yyrecoverSyntaxError (&yystack]b4_user_args[);
yyreturn:
if (yychar != YYEMPTY)
yydestruct ("Cleanup: discarding lookahead",
- YYTRANSLATE (yychar), &yylval]b4_locuser_args([&yylloc])[);
+ YYTRANSLATE (yychar), &yylval]b4_locuser_args([&yylloc])[);
/* If the stack is well-formed, pop the stack until it is empty,
destroying its entries as we go. But free the stack regardless
{
yyGLRState** yystates = yystack.yytops.yystates;
if (yystates)
- {
- size_t yysize = yystack.yytops.yysize;
- size_t yyk;
- for (yyk = 0; yyk < yysize; yyk += 1)
- if (yystates[yyk])
- {
- while (yystates[yyk])
- {
- yyGLRState *yys = yystates[yyk];
-]b4_locations_if([[ yystack.yyerror_range[1].yystate.yyloc = yys->yyloc;]]
-)[ if (yys->yypred != YY_NULL)
- yydestroyGLRState ("Cleanup: popping", yys]b4_user_args[);
- yystates[yyk] = yys->yypred;
- yystack.yynextFree -= 1;
- yystack.yyspaceLeft += 1;
- }
- break;
- }
- }
+ {
+ size_t yysize = yystack.yytops.yysize;
+ size_t yyk;
+ for (yyk = 0; yyk < yysize; yyk += 1)
+ if (yystates[yyk])
+ {
+ while (yystates[yyk])
+ {
+ yyGLRState *yys = yystates[yyk];
+]b4_locations_if([[ yystack.yyerror_range[1].yystate.yyloc = yys->yyloc;]]
+)[ if (yys->yypred != YY_NULL)
+ yydestroyGLRState ("Cleanup: popping", yys]b4_user_args[);
+ yystates[yyk] = yys->yypred;
+ yystack.yynextFree -= 1;
+ yystack.yyspaceLeft += 1;
+ }
+ break;
+ }
+ }
yyfreeGLRStack (&yystack);
}
yypstates (yystackp->yytops.yystates[yyk]);
}
-#define YYINDEX(YYX) \
+#define YYINDEX(YYX) \
((YYX) == YY_NULL ? -1 : (yyGLRStackItem*) (YYX) - yystackp->yyitems)
YYFPRINTF (stderr, "%3lu. ",
(unsigned long int) (yyp - yystackp->yyitems));
if (*(yybool *) yyp)
- {
- YYFPRINTF (stderr, "Res: %d, LR State: %d, posn: %lu, pred: %ld",
- yyp->yystate.yyresolved, yyp->yystate.yylrState,
- (unsigned long int) yyp->yystate.yyposn,
- (long int) YYINDEX (yyp->yystate.yypred));
- if (! yyp->yystate.yyresolved)
- YYFPRINTF (stderr, ", firstVal: %ld",
- (long int) YYINDEX (yyp->yystate
+ {
+ YYFPRINTF (stderr, "Res: %d, LR State: %d, posn: %lu, pred: %ld",
+ yyp->yystate.yyresolved, yyp->yystate.yylrState,
+ (unsigned long int) yyp->yystate.yyposn,
+ (long int) YYINDEX (yyp->yystate.yypred));
+ if (! yyp->yystate.yyresolved)
+ YYFPRINTF (stderr, ", firstVal: %ld",
+ (long int) YYINDEX (yyp->yystate
.yysemantics.yyfirstVal));
- }
+ }
else
- {
- YYFPRINTF (stderr, "Option. rule: %d, state: %ld, next: %ld",
- yyp->yyoption.yyrule - 1,
- (long int) YYINDEX (yyp->yyoption.yystate),
- (long int) YYINDEX (yyp->yyoption.yynext));
- }
+ {
+ YYFPRINTF (stderr, "Option. rule: %d, state: %ld, next: %ld",
+ yyp->yyoption.yyrule - 1,
+ (long int) YYINDEX (yyp->yyoption.yystate),
+ (long int) YYINDEX (yyp->yyoption.yynext));
+ }
YYFPRINTF (stderr, "\n");
}
YYFPRINTF (stderr, "Tops:");
for (yyi = 0; yyi < yystackp->yytops.yysize; yyi += 1)
YYFPRINTF (stderr, "%lu: %ld; ", (unsigned long int) yyi,
- (long int) YYINDEX (yystackp->yytops.yystates[yyi]));
+ (long int) YYINDEX (yystackp->yytops.yystates[yyi]));
YYFPRINTF (stderr, "\n");
}
#endif
-]
-
-b4_epilogue
+]b4_epilogue[]dnl
dnl
dnl glr.cc produces its own header.
dnl
b4_locations_if([b4_pure_if([],
[extern YYLTYPE ]b4_prefix[lloc;])
])
-])])
+])])[]dnl
m4_divert_pop(0)
* Simple GLR Parsers:: Using GLR parsers on unambiguous grammars.
* Merging GLR Parses:: Using GLR parsers to resolve ambiguities.
-* GLR Semantic Actions:: Deferred semantic actions have special concerns.
+* GLR Semantic Actions:: Considerations for semantic values and deferred actions.
+* Semantic Predicates:: Controlling a parse with arbitrary computations.
* Compiler Requirements:: GLR parsers require a modern C compiler.
Examples
Grammar Rules for @code{rpcalc}
-* Rpcalc Input::
-* Rpcalc Line::
-* Rpcalc Expr::
+* Rpcalc Input:: Explanation of the @code{input} nonterminal
+* Rpcalc Line:: Explanation of the @code{line} nonterminal
+* Rpcalc Expr:: Explanation of the @code{expr} nonterminal
Location Tracking Calculator: @code{ltcalc}
* Mfcalc Declarations:: Bison declarations for multi-function calculator.
* Mfcalc Rules:: Grammar rules for the calculator.
* Mfcalc Symbol Table:: Symbol table management subroutines.
+* Mfcalc Lexer:: The lexical analyzer.
+* Mfcalc Main:: The controlling function.
Bison Grammar Files
Operator Precedence
* Why Precedence:: An example showing why precedence is needed.
-* Using Precedence:: How to specify precedence in Bison grammars.
+* Using Precedence:: How to specify precedence and associativity.
+* Precedence Only:: How to specify precedence only.
* Precedence Examples:: How these features are used in the previous example.
* How Precedence:: How they work.
@menu
* Simple GLR Parsers:: Using GLR parsers on unambiguous grammars.
* Merging GLR Parses:: Using GLR parsers to resolve ambiguities.
-* GLR Semantic Actions:: Deferred semantic actions have special concerns.
+* GLR Semantic Actions:: Considerations for semantic values and deferred actions.
+* Semantic Predicates:: Controlling a parse with arbitrary computations.
* Compiler Requirements:: GLR parsers require a modern C compiler.
@end menu
@node GLR Semantic Actions
@subsection GLR Semantic Actions
+The nature of GLR parsing and the structure of the generated
+parsers give rise to certain restrictions on semantic values and actions.
+
+@subsubsection Deferred semantic actions
@cindex deferred semantic actions
By definition, a deferred semantic action is not performed at the same time as
the associated reduction.
to invoke @code{yyclearin} (@pxref{Action Features}) or to attempt to free
memory referenced by @code{yylval}.
+@subsubsection YYERROR
@findex YYERROR
@cindex GLR parsers and @code{YYERROR}
Another Bison feature requiring special consideration is @code{YYERROR}
initiate error recovery.
During deterministic GLR operation, the effect of @code{YYERROR} is
the same as its effect in a deterministic parser.
-In a deferred semantic action, its effect is undefined.
-@c The effect is probably a syntax error at the split point.
+The effect in a deferred action is similar, but the precise point of the
+error is undefined; instead, the parser reverts to deterministic operation,
+selecting an unspecified stack on which to continue with a syntax error.
+In a semantic predicate (see @ref{Semantic Predicates}) during nondeterministic
+parsing, @code{YYERROR} silently prunes
+the parse that invoked the test.
+
+@subsubsection Restrictions on semantic values and locations
+GLR parsers require that you use POD (Plain Old Data) types for
+semantic values and location types when using the generated parsers as
+C++ code.
+
+@node Semantic Predicates
+@subsection Controlling a Parse with Arbitrary Predicates
+@findex %?
+@cindex Semantic predicates in GLR parsers
+
+In addition to the @code{%dprec} and @code{%merge} directives,
+GLR parsers
+allow you to reject parses on the basis of arbitrary computations executed
+in user code, without having Bison treat this rejection as an error
+if there are alternative parses. (This feature is experimental and may
+evolve. We welcome user feedback.) For example,
+
+@example
+widget:
+ %?@{ new_syntax @} "widget" id new_args @{ $$ = f($3, $4); @}
+| %?@{ !new_syntax @} "widget" id old_args @{ $$ = f($3, $4); @}
+;
+@end example
+
+@noindent
+is one way to allow the same parser to handle two different syntaxes for
+widgets. The clause preceded by @code{%?} is treated like an ordinary
+action, except that its text is treated as an expression and is always
+evaluated immediately (even when in nondeterministic mode). If the
+expression yields 0 (false), the clause is treated as a syntax error,
+which, in a nondeterministic parser, causes the stack in which it is reduced
+to die. In a deterministic parser, it acts like YYERROR.
+
+As the example shows, predicates otherwise look like semantic actions, and
+therefore you must be take them into account when determining the numbers
+to use for denoting the semantic values of right-hand side symbols.
+Predicate actions, however, have no defined value, and may not be given
+labels.
+
+There is a subtle difference between semantic predicates and ordinary
+actions in nondeterministic mode, since the latter are deferred.
+For example, we could try to rewrite the previous example as
+
+@example
+widget:
+ @{ if (!new_syntax) YYERROR; @}
+ "widget" id new_args @{ $$ = f($3, $4); @}
+| @{ if (new_syntax) YYERROR; @}
+ "widget" id old_args @{ $$ = f($3, $4); @}
+;
+@end example
-Also, see @ref{Location Default Action, ,Default Action for Locations}, which
-describes a special usage of @code{YYLLOC_DEFAULT} in GLR parsers.
+@noindent
+(reversing the sense of the predicate tests to cause an error when they are
+false). However, this
+does @emph{not} have the same effect if @code{new_args} and @code{old_args}
+have overlapping syntax.
+Since the mid-rule actions testing @code{new_syntax} are deferred,
+a GLR parser first encounters the unresolved ambiguous reduction
+for cases where @code{new_args} and @code{old_args} recognize the same string
+@emph{before} performing the tests of @code{new_syntax}. It therefore
+reports an error.
+
+Finally, be careful in writing predicates: deferred actions have not been
+evaluated, so that using them in a predicate will have undefined effects.
@node Compiler Requirements
@subsection Considerations when Compiling GLR Parsers
Here are the C and Bison declarations for the reverse polish notation
calculator. As in C, comments are placed between @samp{/*@dots{}*/}.
+@comment file: rpcalc.y
@example
/* Reverse polish notation calculator. */
%@{
#define YYSTYPE double
+ #include <stdio.h>
#include <math.h>
int yylex (void);
void yyerror (char const *);
Here are the grammar rules for the reverse polish notation calculator.
+@comment file: rpcalc.y
@example
@group
input:
rule are referred to as @code{$1}, @code{$2}, and so on.
@menu
-* Rpcalc Input::
-* Rpcalc Line::
-* Rpcalc Expr::
+* Rpcalc Input:: Explanation of the @code{input} nonterminal
+* Rpcalc Line:: Explanation of the @code{line} nonterminal
+* Rpcalc Expr:: Explanation of the @code{expr} nonterminal
@end menu
@node Rpcalc Input
Here is the code for the lexical analyzer:
+@comment file: rpcalc.y
@example
@group
/* The lexical analyzer returns a double floating point
kept to the bare minimum. The only requirement is that it call
@code{yyparse} to start the process of parsing.
+@comment file: rpcalc.y
@example
@group
int
@code{yyerror} (@pxref{Interface, ,Parser C-Language Interface}), so
here is the definition we will use:
+@comment file: rpcalc.y
@example
@group
#include <stdio.h>
@example
$ @kbd{rpcalc}
@kbd{4 9 +}
-13
+@result{} 13
@kbd{3 7 + 3 4 5 *+-}
--13
+@result{} -13
@kbd{3 7 + 3 4 5 * + - n} @r{Note the unary minus, @samp{n}}
-13
+@result{} 13
@kbd{5 6 / 4 n +}
--3.166666667
+@result{} -3.166666667
@kbd{3 4 ^} @r{Exponentiation}
-81
+@result{} 81
@kbd{^D} @r{End-of-file indicator}
$
@end example
%token NUM
%left '-' '+'
%left '*' '/'
-%left NEG /* negation--unary minus */
-%right '^' /* exponentiation */
+%precedence NEG /* negation--unary minus */
+%right '^' /* exponentiation */
@end group
%% /* The grammar follows. */
types and says they are left-associative operators. The declarations
@code{%left} and @code{%right} (right associativity) take the place of
@code{%token} which is used to declare a token type name without
-associativity. (These tokens are single-character literals, which
+associativity/precedence. (These tokens are single-character literals, which
ordinarily don't need to be declared. We declare them here to specify
-the associativity.)
+the associativity/precedence.)
Operator precedence is determined by the line ordering of the
declarations; the higher the line number of the declaration (lower on
the page or screen), the higher the precedence. Hence, exponentiation
has the highest precedence, unary minus (@code{NEG}) is next, followed
-by @samp{*} and @samp{/}, and so on. @xref{Precedence, ,Operator
+by @samp{*} and @samp{/}, and so on. Unary minus is not associative,
+only precedence matters (@code{%precedence}. @xref{Precedence, ,Operator
Precedence}.
The other important new feature is the @code{%prec} in the grammar
%left '-' '+'
%left '*' '/'
-%left NEG
+%precedence NEG
%right '^'
%% /* The grammar follows. */
Here is a sample session with the multi-function calculator:
@example
+@group
$ @kbd{mfcalc}
@kbd{pi = 3.141592653589}
-3.1415926536
+@result{} 3.1415926536
+@end group
+@group
@kbd{sin(pi)}
-0.0000000000
+@result{} 0.0000000000
+@end group
@kbd{alpha = beta1 = 2.3}
-2.3000000000
+@result{} 2.3000000000
@kbd{alpha}
-2.3000000000
+@result{} 2.3000000000
@kbd{ln(alpha)}
-0.8329091229
+@result{} 0.8329091229
@kbd{exp(ln(beta1))}
-2.3000000000
+@result{} 2.3000000000
$
@end example
* Mfcalc Declarations:: Bison declarations for multi-function calculator.
* Mfcalc Rules:: Grammar rules for the calculator.
* Mfcalc Symbol Table:: Symbol table management subroutines.
+* Mfcalc Lexer:: The lexical analyzer.
+* Mfcalc Main:: The controlling function.
@end menu
@node Mfcalc Declarations
@example
@group
%@{
- #include <math.h> /* For math functions, cos(), sin(), etc. */
- #include "calc.h" /* Contains definition of `symrec'. */
+ #include <stdio.h> /* For printf, etc. */
+ #include <math.h> /* For pow, used in the grammar. */
+ #include "calc.h" /* Contains definition of `symrec'. */
int yylex (void);
void yyerror (char const *);
%@}
%right '='
%left '-' '+'
%left '*' '/'
-%left NEG /* negation--unary minus */
-%right '^' /* exponentiation */
+%precedence NEG /* negation--unary minus */
+%right '^' /* exponentiation */
@end group
@end example
@end group
@end example
-The new version of @code{main} includes a call to @code{init_table}, a
-function that initializes the symbol table. Here it is, and
-@code{init_table} as well:
+The new version of @code{main} will call @code{init_table} to initialize
+the symbol table:
@comment file: mfcalc.y: 3
@example
-#include <stdio.h>
-
-@group
-/* Called by yyparse on error. */
-void
-yyerror (char const *s)
-@{
- printf ("%s\n", s);
-@}
-@end group
-
@group
struct init
@{
@group
struct init const arith_fncts[] =
@{
- "sin", sin,
- "cos", cos,
- "atan", atan,
- "ln", log,
- "exp", exp,
- "sqrt", sqrt,
- 0, 0
+ @{ "atan", atan @},
+ @{ "cos", cos @},
+ @{ "exp", exp @},
+ @{ "ln", log @},
+ @{ "sin", sin @},
+ @{ "sqrt", sqrt @},
+ @{ 0, 0 @},
@};
@end group
@group
/* Put arithmetic functions in table. */
+static
void
init_table (void)
@{
@}
@}
@end group
-
-@group
-int
-main (void)
-@{
- init_table ();
- return yyparse ();
-@}
-@end group
@end example
By simply editing the initialization list and adding the necessary include
symrec *ptr;
for (ptr = sym_table; ptr != (symrec *) 0;
ptr = (symrec *)ptr->next)
- if (strcmp (ptr->name,sym_name) == 0)
+ if (strcmp (ptr->name, sym_name) == 0)
return ptr;
return 0;
@}
@end group
@end example
+@node Mfcalc Lexer
+@subsection The @code{mfcalc} Lexer
+
The function @code{yylex} must now recognize variables, numeric values, and
the single-character arithmetic operators. Strings of alphanumeric
characters with a leading letter are recognized as either variables or
symrec *s;
int i;
@end group
-
if (!symbuf)
symbuf = (char *) malloc (length + 1);
@end group
@end example
+@node Mfcalc Main
+@subsection The @code{mfcalc} Main
+
The error reporting function is unchanged, and the new version of
@code{main} includes a call to @code{init_table} and sets the @code{yydebug}
on user demand (@xref{Tracing, , Tracing Your Parser}, for details):
the parser, so that the function @code{yylex} (if it is in this file)
can use the name @var{name} to stand for this token type's code.
-Alternatively, you can use @code{%left}, @code{%right}, or
+Alternatively, you can use @code{%left}, @code{%right},
+@code{%precedence}, or
@code{%nonassoc} instead of @code{%token}, if you wish to specify
associativity and precedence. @xref{Precedence Decl, ,Operator
Precedence}.
@cindex declaring operator precedence
@cindex operator precedence, declaring
-Use the @code{%left}, @code{%right} or @code{%nonassoc} declaration to
+Use the @code{%left}, @code{%right}, @code{%nonassoc}, or
+@code{%precedence} declaration to
declare a token and specify its precedence and associativity, all at
once. These are called @dfn{precedence declarations}.
@xref{Precedence, ,Operator Precedence}, for general information on
means that @samp{@var{x} @var{op} @var{y} @var{op} @var{z}} is
considered a syntax error.
+@code{%precedence} gives only precedence to the @var{symbols}, and
+defines no associativity at all. Use this to define precedence only,
+and leave any potential conflict due to associativity enabled.
+
@item
The precedence of an operator determines how it nests with other operators.
All the tokens declared in a single precedence declaration have equal
including @code{yylval} and @code{yylloc}.)
Alternatively, you can generate a pure, reentrant parser. The Bison
-declaration @code{%define api.pure} says that you want the parser to be
+declaration @samp{%define api.pure} says that you want the parser to be
reentrant. It looks like this:
@example
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 api.push-pull push} declaration with the
-@code{%define api.push-pull both} declaration. Doing this will create all of
+you should replace the @samp{%define api.push-pull push} declaration with the
+@samp{%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 api.push-pull both} declaration slower than the normal
+@samp{%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
yypstate_delete (ps);
@end example
-Adding the @code{%define api.pure} declaration does exactly the same thing to
-the generated parser with @code{%define api.push-pull both} as it did for
-@code{%define api.push-pull push}.
+Adding the @samp{%define api.pure} declaration does exactly the same thing to
+the generated parser with @samp{%define api.push-pull both} as it did for
+@samp{%define api.push-pull push}.
@node Decl Summary
@subsection Bison Declaration Summary
@end deffn
@deffn {Directive} %debug
-In the parser implementation file, define the macro @code{YYDEBUG} to
-1 if it is not already defined, so that the debugging facilities are
-compiled. @xref{Tracing, ,Tracing Your Parser}.
+Instrument the output parser for traces. Obsoleted by @samp{%define
+parse.trace}.
+@xref{Tracing, ,Tracing Your Parser}.
@end deffn
@deffn {Directive} %define @var{variable}
@code{yypstate_new} and @code{yypstate_delete} will
also be renamed. For example, if you use @samp{%name-prefix "c_"}, the
names become @code{c_parse}, @code{c_lex}, and so on.
-For C++ parsers, see the @code{%define namespace} documentation in this
+For C++ parsers, see the @samp{%define api.namespace} documentation in this
section.
@xref{Multiple Parsers, ,Multiple Parsers in the Same Program}.
@end deffn
@end deffn
@deffn {Directive} %pure-parser
-Deprecated version of @code{%define api.pure} (@pxref{%define
+Deprecated version of @samp{%define api.pure} (@pxref{%define
Summary,,api.pure}), for which Bison is more careful to warn about
unreasonable usage.
@end deffn
Unaccepted @var{variable}s produce an error.
Some of the accepted @var{variable}s are:
-@itemize @bullet
+@table @code
+@c ================================================== api.namespace
+@item api.namespace
+@findex %define api.namespace
+@itemize
+@item Languages(s): C++
+
+@item Purpose: Specify the namespace for the parser class.
+For example, if you specify:
+
+@example
+%define api.namespace "foo::bar"
+@end example
+
+Bison uses @code{foo::bar} verbatim in references such as:
+
+@example
+foo::bar::parser::semantic_type
+@end example
+
+However, to open a namespace, Bison removes any leading @code{::} and then
+splits on any remaining occurrences:
+
+@example
+namespace foo @{ namespace bar @{
+ class position;
+ class location;
+@} @}
+@end example
+
+@item Accepted Values:
+Any absolute or relative C++ namespace reference without a trailing
+@code{"::"}. For example, @code{"foo"} or @code{"::foo::bar"}.
+
+@item Default Value:
+The value specified by @code{%name-prefix}, which defaults to @code{yy}.
+This usage of @code{%name-prefix} is for backward compatibility and can
+be confusing since @code{%name-prefix} also specifies the textual prefix
+for the lexical analyzer function. Thus, if you specify
+@code{%name-prefix}, it is best to also specify @samp{%define
+api.namespace} so that @code{%name-prefix} @emph{only} affects the
+lexical analyzer function. For example, if you specify:
+
+@example
+%define api.namespace "foo"
+%name-prefix "bar::"
+@end example
+
+The parser namespace is @code{foo} and @code{yylex} is referenced as
+@code{bar::lex}.
+@end itemize
+@c namespace
+
+
+
@c ================================================== api.pure
@item api.pure
@findex %define api.pure
@item Default Value: @code{false}
@end itemize
+@c api.pure
+
+
+@c ================================================== api.push-pull
@item api.push-pull
@findex %define api.push-pull
@item Default Value: @code{pull}
@end itemize
+@c api.push-pull
+
+
+
+@c ================================================== api.tokens.prefix
+@item api.tokens.prefix
+@findex %define api.tokens.prefix
+
+@itemize
+@item Languages(s): all
+
+@item Purpose:
+Add a prefix to the token names when generating their definition in the
+target language. For instance
+
+@example
+%token FILE for ERROR
+%define api.tokens.prefix "TOK_"
+%%
+start: FILE for ERROR;
+@end example
+
+@noindent
+generates the definition of the symbols @code{TOK_FILE}, @code{TOK_for},
+and @code{TOK_ERROR} in the generated source files. In particular, the
+scanner must use these prefixed token names, while the grammar itself
+may still use the short names (as in the sample rule given above). The
+generated informational files (@file{*.output}, @file{*.xml},
+@file{*.dot}) are not modified by this prefix. See @ref{Calc++ Parser}
+and @ref{Calc++ Scanner}, for a complete example.
+
+@item Accepted Values:
+Any string. Should be a valid identifier prefix in the target language,
+in other words, it should typically be an identifier itself (sequence of
+letters, underscores, and ---not at the beginning--- digits).
+
+@item Default Value:
+empty
+@end itemize
+@c api.tokens.prefix
+
+
+@c ================================================== lex_symbol
+@item lex_symbol
+@findex %define lex_symbol
+
+@itemize @bullet
+@item Language(s):
+C++
+
+@item Purpose:
+When variant-based semantic values are enabled (@pxref{C++ Variants}),
+request that symbols be handled as a whole (type, value, and possibly
+location) in the scanner. @xref{Complete Symbols}, for details.
+
+@item Accepted Values:
+Boolean.
+
+@item Default Value:
+@code{false}
+@end itemize
+@c lex_symbol
+
@c ================================================== lr.default-reductions
@item Accepted Values: Boolean
@item Default Value: @code{false}
@end itemize
+@c lr.keep-unreachable-states
@c ================================================== lr.type
@item Default Value: @code{lalr}
@end itemize
+
+@c ================================================== namespace
@item namespace
@findex %define namespace
+Obsoleted by @code{api.namespace}
+@c namespace
-@itemize
-@item Languages(s): C++
-@item Purpose: Specify the namespace for the parser class.
-For example, if you specify:
+@c ================================================== parse.assert
+@item parse.assert
+@findex %define parse.assert
-@smallexample
-%define namespace "foo::bar"
-@end smallexample
+@itemize
+@item Languages(s): C++
-Bison uses @code{foo::bar} verbatim in references such as:
+@item Purpose: Issue runtime assertions to catch invalid uses.
+In C++, when variants are used (@pxref{C++ Variants}), symbols must be
+constructed and
+destroyed properly. This option checks these constraints.
-@smallexample
-foo::bar::parser::semantic_type
-@end smallexample
+@item Accepted Values: Boolean
-However, to open a namespace, Bison removes any leading @code{::} and then
-splits on any remaining occurrences:
+@item Default Value: @code{false}
+@end itemize
+@c parse.assert
-@smallexample
-namespace foo @{ namespace bar @{
- class position;
- class location;
-@} @}
-@end smallexample
-
-@item Accepted Values: Any absolute or relative C++ namespace reference without
-a trailing @code{"::"}.
-For example, @code{"foo"} or @code{"::foo::bar"}.
-
-@item Default Value: The value specified by @code{%name-prefix}, which defaults
-to @code{yy}.
-This usage of @code{%name-prefix} is for backward compatibility and can be
-confusing since @code{%name-prefix} also specifies the textual prefix for the
-lexical analyzer function.
-Thus, if you specify @code{%name-prefix}, it is best to also specify
-@code{%define namespace} so that @code{%name-prefix} @emph{only} affects the
-lexical analyzer function.
-For example, if you specify:
-@smallexample
-%define namespace "foo"
-%name-prefix "bar::"
-@end smallexample
+@c ================================================== parse.error
+@item parse.error
+@findex %define parse.error
+@itemize
+@item Languages(s):
+all
+@item Purpose:
+Control the kind of error messages passed to the error reporting
+function. @xref{Error Reporting, ,The Error Reporting Function
+@code{yyerror}}.
+@item Accepted Values:
+@itemize
+@item @code{simple}
+Error messages passed to @code{yyerror} are simply @w{@code{"syntax
+error"}}.
+@item @code{verbose}
+Error messages report the unexpected token, and possibly the expected ones.
+However, this report can often be incorrect when LAC is not enabled
+(@pxref{LAC}).
+@end itemize
-The parser namespace is @code{foo} and @code{yylex} is referenced as
-@code{bar::lex}.
+@item Default Value:
+@code{simple}
@end itemize
+@c parse.error
+
@c ================================================== parse.lac
@item parse.lac
@item Accepted Values: @code{none}, @code{full}
@item Default Value: @code{none}
@end itemize
+@c parse.lac
+
+@c ================================================== parse.trace
+@item parse.trace
+@findex %define parse.trace
+
+@itemize
+@item Languages(s): C, C++
+
+@item Purpose: Require parser instrumentation for tracing.
+In C/C++, define the macro @code{YYDEBUG} to 1 in the parser implementation
+file if it is not already defined, so that the debugging facilities are
+compiled. @xref{Tracing, ,Tracing Your Parser}.
+
+@item Accepted Values: Boolean
+
+@item Default Value: @code{false}
@end itemize
+@c parse.trace
+
+@c ================================================== variant
+@item variant
+@findex %define variant
+
+@itemize @bullet
+@item Language(s):
+C++
+
+@item Purpose:
+Request variant-based semantic values.
+@xref{C++ Variants}.
+
+@item Accepted Values:
+Boolean.
+
+@item Default Value:
+@code{false}
+@end itemize
+@c variant
+@end table
@node %code Summary
Not all qualifiers are accepted for all target languages. Unaccepted
qualifiers produce an error. Some of the accepted qualifiers are:
-@itemize @bullet
+@table @code
@item requires
@findex %code requires
@item Location(s): The parser Java file after any Java package directive and
before any class definitions.
@end itemize
-@end itemize
+@end table
Though we say the insertion locations are language-dependent, they are
technically skeleton-dependent. Writers of non-standard skeletons
parameter information to it in a reentrant way. To do so, use the
declaration @code{%parse-param}:
-@deffn {Directive} %parse-param @{@var{argument-declaration}@}
+@deffn {Directive} %parse-param @{@var{argument-declaration}@} @dots{}
@findex %parse-param
-Declare that an argument declared by the braced-code
-@var{argument-declaration} is an additional @code{yyparse} argument.
+Declare that one or more
+@var{argument-declaration} are additional @code{yyparse} arguments.
The @var{argument-declaration} is used when declaring
functions or prototypes. The last identifier in
@var{argument-declaration} must be the argument name.
Here's an example. Write this in the parser:
@example
-%parse-param @{int *nastiness@}
-%parse-param @{int *randomness@}
+%parse-param @{int *nastiness@} @{int *randomness@}
@end example
@noindent
More user feedback will help to stabilize it.)
You call the function @code{yypush_parse} to parse a single token. This
-function is available if either the @code{%define api.push-pull push} or
-@code{%define api.push-pull both} declaration is used.
+function is available if either the @samp{%define api.push-pull push} or
+@samp{%define api.push-pull both} declaration is used.
@xref{Push Decl, ,A Push Parser}.
@deftypefun int yypush_parse (yypstate *yyps)
More user feedback will help to stabilize it.)
You call the function @code{yypull_parse} to parse the rest of the input
-stream. This function is available if the @code{%define api.push-pull both}
+stream. This function is available if the @samp{%define api.push-pull both}
declaration is used.
@xref{Push Decl, ,A Push Parser}.
More user feedback will help to stabilize it.)
You call the function @code{yypstate_new} to create a new parser instance.
-This function is available if either the @code{%define api.push-pull push} or
-@code{%define api.push-pull both} declaration is used.
+This function is available if either the @samp{%define api.push-pull push} or
+@samp{%define api.push-pull both} declaration is used.
@xref{Push Decl, ,A Push Parser}.
- @deftypefun yypstate *yypstate_new (void)
+ @deftypefun {yypstate*} yypstate_new (void)
The function will return a valid parser instance if there was memory available
or 0 if no memory was available.
In impure mode, it will also return 0 if a parser instance is currently
More user feedback will help to stabilize it.)
You call the function @code{yypstate_delete} to delete a parser instance.
-function is available if either the @code{%define api.push-pull push} or
-@code{%define api.push-pull both} declaration is used.
+function is available if either the @samp{%define api.push-pull push} or
+@samp{%define api.push-pull both} declaration is used.
@xref{Push Decl, ,A Push Parser}.
@deftypefun void yypstate_delete (yypstate *yyps)
@node Pure Calling
@subsection Calling Conventions for Pure Parsers
-When you use the Bison declaration @code{%define api.pure} to request a
+When you use the Bison declaration @samp{%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
this case, omit the second argument; @code{yylex} will be called with
only one argument.
-
-If you wish to pass the additional parameter data to @code{yylex}, use
+If you wish to pass additional arguments to @code{yylex}, use
@code{%lex-param} just like @code{%parse-param} (@pxref{Parser
-Function}).
+Function}). To pass additional arguments to both @code{yylex} and
+@code{yyparse}, use @code{%param}.
-@deffn {Directive} lex-param @{@var{argument-declaration}@}
+@deffn {Directive} %lex-param @{@var{argument-declaration}@} @dots{}
@findex %lex-param
-Declare that the braced-code @var{argument-declaration} is an
-additional @code{yylex} argument declaration.
+Specify that @var{argument-declaration} are additional @code{yylex} argument
+declarations. You may pass one or more such declarations, which is
+equivalent to repeating @code{%lex-param}.
+@end deffn
+
+@deffn {Directive} %param @{@var{argument-declaration}@} @dots{}
+@findex %param
+Specify that @var{argument-declaration} are additional
+@code{yylex}/@code{yyparse} argument declaration. This is equivalent to
+@samp{%lex-param @{@var{argument-declaration}@} @dots{} %parse-param
+@{@var{argument-declaration}@} @dots{}}. You may pass one or more
+declarations, which is equivalent to repeating @code{%param}.
@end deffn
For instance:
@example
-%parse-param @{int *nastiness@}
-%lex-param @{int *nastiness@}
-%parse-param @{int *randomness@}
+%lex-param @{scanner_mode *mode@}
+%parse-param @{parser_mode *mode@}
+%param @{environment_type *env@}
@end example
@noindent
results in the following signature:
@example
-int yylex (int *nastiness);
-int yyparse (int *nastiness, int *randomness);
+int yylex (scanner_mode *mode, environment_type *env);
+int yyparse (parser_mode *mode, environment_type *env);
@end example
-If @code{%define api.pure} is added:
+If @samp{%define api.pure} is added:
@example
-int yylex (YYSTYPE *lvalp, int *nastiness);
-int yyparse (int *nastiness, int *randomness);
+int yylex (YYSTYPE *lvalp, scanner_mode *mode, environment_type *env);
+int yyparse (parser_mode *mode, environment_type *env);
@end example
@noindent
-and finally, if both @code{%define api.pure} and @code{%locations} are used:
+and finally, if both @samp{%define api.pure} and @code{%locations} are used:
@example
-int yylex (YYSTYPE *lvalp, YYLTYPE *llocp, int *nastiness);
-int yyparse (int *nastiness, int *randomness);
+int yylex (YYSTYPE *lvalp, YYLTYPE *llocp,
+ scanner_mode *mode, environment_type *env);
+int yyparse (parser_mode *mode, environment_type *env);
@end example
@node Error Reporting
@cindex parse error
@cindex syntax error
-The Bison parser detects a @dfn{syntax error} or @dfn{parse error}
+The Bison parser detects a @dfn{syntax error} (or @dfn{parse error})
whenever it reads a token which cannot satisfy any syntax rule. An
action in the grammar can also explicitly proclaim an error, using the
macro @code{YYERROR} (@pxref{Action Features, ,Special Features for Use
receives one argument. For a syntax error, the string is normally
@w{@code{"syntax error"}}.
-@findex %error-verbose
-If you invoke the directive @code{%error-verbose} in the Bison declarations
+@findex %define parse.error
+If you invoke @samp{%define parse.error verbose} in the Bison declarations
section (@pxref{Bison Declarations, ,The Bison Declarations Section}), then
Bison provides a more verbose and specific error message string instead of
just plain @w{@code{"syntax error"}}. However, that message sometimes
Finally, 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{%define api.pure} are pure.
+@samp{%define api.pure} are pure.
I.e.:
@example
@xref{Action Types, ,Data Types of Values in Actions}.
@end deffn
- @deffn {Macro} YYABORT;
+ @deffn {Macro} YYABORT @code{;}
Return immediately from @code{yyparse}, indicating failure.
@xref{Parser Function, ,The Parser Function @code{yyparse}}.
@end deffn
- @deffn {Macro} YYACCEPT;
+ @deffn {Macro} YYACCEPT @code{;}
Return immediately from @code{yyparse}, indicating success.
@xref{Parser Function, ,The Parser Function @code{yyparse}}.
@end deffn
- @deffn {Macro} YYBACKUP (@var{token}, @var{value});
+ @deffn {Macro} YYBACKUP (@var{token}, @var{value})@code{;}
@findex YYBACKUP
Unshift a token. This macro is allowed only for rules that reduce
a single value, and only when there is no lookahead token.
@end deffn
@deffn {Macro} YYEMPTY
- @vindex YYEMPTY
Value stored in @code{yychar} when there is no lookahead token.
@end deffn
@deffn {Macro} YYEOF
- @vindex YYEOF
Value stored in @code{yychar} when the lookahead is the end of the input
stream.
@end deffn
- @deffn {Macro} YYERROR;
- @findex YYERROR
+ @deffn {Macro} YYERROR @code{;}
Cause an immediate syntax error. This statement initiates error
recovery just as if the parser itself had detected an error; however, it
does not call @code{yyerror}, and does not print any message. If you
@xref{Lookahead, ,Lookahead Tokens}.
@end deffn
- @deffn {Macro} yyclearin;
+ @deffn {Macro} yyclearin @code{;}
Discard the current lookahead token. This is useful primarily in
error rules.
Do not invoke @code{yyclearin} in a deferred semantic action (@pxref{GLR
@xref{Error Recovery}.
@end deffn
- @deffn {Macro} yyerrok;
+ @deffn {Macro} yyerrok @code{;}
Resume generating error messages immediately for subsequent syntax
errors. This is useful primarily in error rules.
@xref{Error Recovery}.
@menu
* Why Precedence:: An example showing why precedence is needed.
-* Using Precedence:: How to specify precedence in Bison grammars.
+* Using Precedence:: How to specify precedence and associativity.
+* Precedence Only:: How to specify precedence only.
* Precedence Examples:: How these features are used in the previous example.
* How Precedence:: How they work.
@end menu
@node Using Precedence
@subsection Specifying Operator Precedence
@findex %left
-@findex %right
@findex %nonassoc
+@findex %precedence
+@findex %right
Bison allows you to specify these choices with the operator precedence
declarations @code{%left} and @code{%right}. Each such declaration
them right-associative. A third alternative is @code{%nonassoc}, which
declares that it is a syntax error to find the same operator twice ``in a
row''.
+The last alternative, @code{%precedence}, allows to define only
+precedence and no associativity at all. As a result, any
+associativity-related conflict that remains will be reported as an
+compile-time error. The directive @code{%nonassoc} creates run-time
+error: using the operator in a associative way is a syntax error. The
+directive @code{%precedence} creates compile-time errors: an operator
+@emph{can} be involved in an associativity-related conflict, contrary to
+what expected the grammar author.
The relative precedence of different operators is controlled by the
-order in which they are declared. The first @code{%left} or
-@code{%right} declaration in the file declares the operators whose
+order in which they are declared. The first precedence/associativity
+declaration in the file declares the operators whose
precedence is lowest, the next such declaration declares the operators
whose precedence is a little higher, and so on.
+@node Precedence Only
+@subsection Specifying Precedence Only
+@findex %precedence
+
+Since POSIX Yacc defines only @code{%left}, @code{%right}, and
+@code{%nonassoc}, which all defines precedence and associativity, little
+attention is paid to the fact that precedence cannot be defined without
+defining associativity. Yet, sometimes, when trying to solve a
+conflict, precedence suffices. In such a case, using @code{%left},
+@code{%right}, or @code{%nonassoc} might hide future (associativity
+related) conflicts that would remain hidden.
+
+The dangling @code{else} ambiguity (@pxref{Shift/Reduce, , Shift/Reduce
+Conflicts}) can be solved explicitly. This shift/reduce conflicts occurs
+in the following situation, where the period denotes the current parsing
+state:
+
+@example
+if @var{e1} then if @var{e2} then @var{s1} . else @var{s2}
+@end example
+
+The conflict involves the reduction of the rule @samp{IF expr THEN
+stmt}, which precedence is by default that of its last token
+(@code{THEN}), and the shifting of the token @code{ELSE}. The usual
+disambiguation (attach the @code{else} to the closest @code{if}),
+shifting must be preferred, i.e., the precedence of @code{ELSE} must be
+higher than that of @code{THEN}. But neither is expected to be involved
+in an associativity related conflict, which can be specified as follows.
+
+@example
+%precedence THEN
+%precedence ELSE
+@end example
+
+The unary-minus is another typical example where associativity is
+usually over-specified, see @ref{Infix Calc, , Infix Notation
+Calculator: @code{calc}}. The @code{%left} directive is traditionally
+used to declare the precedence of @code{NEG}, which is more than needed
+since it also defines its associativity. While this is harmless in the
+traditional example, who knows how @code{NEG} might be used in future
+evolutions of the grammar@dots{}
+
@node Precedence Examples
@subsection Precedence Examples
sign typically has a very high precedence as a unary operator, and a
somewhat lower precedence (lower than multiplication) as a binary operator.
-The Bison precedence declarations, @code{%left}, @code{%right} and
-@code{%nonassoc}, can only be used once for a given token; so a token has
+The Bison precedence declarations
+can only be used once for a given token; so a token has
only one precedence declared in this way. For context-dependent
precedence, you need to use an additional mechanism: the @code{%prec}
modifier for rules.
historical reasons, but that behavior is often not robust. For example, in
the previous section, we discussed the mysterious conflicts that can be
produced by LALR(1), Bison's default parser table construction algorithm.
-Another example is Bison's @code{%error-verbose} directive, which instructs
-the generated parser to produce verbose syntax error messages, which can
-sometimes contain incorrect information.
+Another example is Bison's @code{%define parse.error verbose} directive,
+which instructs the generated parser to produce verbose syntax error
+messages, which can sometimes contain incorrect information.
In this section, we explore several modern features of Bison that allow you
to tune fundamental aspects of the generated LR-based parsers. Some of
Do not allow @code{YYINITDEPTH} to be greater than @code{YYMAXDEPTH}.
-@c FIXME: C++ output.
-Because of semantic differences between C and C++, the deterministic
-parsers in C produced by Bison cannot grow when compiled
-by C++ compilers. In this precise case (compiling a C parser as C++) you are
-suggested to grow @code{YYINITDEPTH}. The Bison maintainers hope to fix
-this deficiency in a future release.
+You can generate a deterministic parser containing C++ user code from
+the default (C) skeleton, as well as from the C++ skeleton
+(@pxref{C++ Parsers}). However, if you do use the default skeleton
+and want to allow the parsing stack to grow,
+be careful not to use semantic types or location types that require
+non-trivial copy constructors.
+The C skeleton bypasses these constructors when copying data to
+new, larger stacks.
@node Error Recovery
@chapter Error Recovery
@item the directive @samp{%debug}
@findex %debug
-Add the @code{%debug} directive (@pxref{Decl Summary, ,Bison
-Declaration Summary}). This is a Bison extension, which will prove
-useful when Bison will output parsers for languages that don't use a
-preprocessor. Unless POSIX and Yacc portability matter to
-you, this is
-the preferred solution.
+Add the @code{%debug} directive (@pxref{Decl Summary, ,Bison Declaration
+Summary}). This Bison extension is maintained for backward
+compatibility with previous versions of Bison.
+
+@item the variable @samp{parse.trace}
+@findex %define parse.trace
+Add the @samp{%define parse.trace} directive (@pxref{%define
+Summary,,parse.trace}), or pass the @option{-Dparse.trace} option
+(@pxref{Bison Options}). This is a Bison extension, which is especially
+useful for languages that don't use a preprocessor. Unless POSIX and Yacc
+portability matter to you, this is the preferred solution.
@end table
-We suggest that you always enable the debug option so that debugging is
+We suggest that you always enable the trace option so that debugging is
always possible.
@findex YYFPRINTF
When run, @command{bison} will create several entities in the @samp{yy}
namespace.
-@findex %define namespace
-Use the @samp{%define namespace} directive to change the namespace
-name, see @ref{%define Summary,,namespace}. The various classes are
-generated in the following files:
+@findex %define api.namespace
+Use the @samp{%define api.namespace} directive to change the namespace name,
+see @ref{%define Summary,,api.namespace}. The various classes are generated
+in the following files:
@table @file
@item position.hh
@itemx location.hh
The definition of the classes @code{position} and @code{location},
-used for location tracking. @xref{C++ Location Values}.
+used for location tracking when enabled. @xref{C++ Location Values}.
@item stack.hh
An auxiliary class @code{stack} used by the parser.
@c - YYSTYPE
@c - Printer and destructor
+Bison supports two different means to handle semantic values in C++. One is
+alike the C interface, and relies on unions (@pxref{C++ Unions}). As C++
+practitioners know, unions are inconvenient in C++, therefore another
+approach is provided, based on variants (@pxref{C++ Variants}).
+
+@menu
+* C++ Unions:: Semantic values cannot be objects
+* C++ Variants:: Using objects as semantic values
+@end menu
+
+@node C++ Unions
+@subsubsection C++ Unions
+
The @code{%union} directive works as for C, see @ref{Union Decl, ,The
Collection of Value Types}. In particular it produces a genuine
-@code{union}@footnote{In the future techniques to allow complex types
-within pseudo-unions (similar to Boost variants) might be implemented to
-alleviate these issues.}, which have a few specific features in C++.
+@code{union}, which have a few specific features in C++.
@itemize @minus
@item
The type @code{YYSTYPE} is defined but its use is discouraged: rather
only means to avoid leaks. @xref{Destructor Decl, , Freeing Discarded
Symbols}.
+@node C++ Variants
+@subsubsection C++ Variants
+
+Starting with version 2.6, Bison provides a @emph{variant} based
+implementation of semantic values for C++. This alleviates all the
+limitations reported in the previous section, and in particular, object
+types can be used without pointers.
+
+To enable variant-based semantic values, set @code{%define} variable
+@code{variant} (@pxref{%define Summary,, variant}). Once this defined,
+@code{%union} is ignored, and instead of using the name of the fields of the
+@code{%union} to ``type'' the symbols, use genuine types.
+
+For instance, instead of
+
+@example
+%union
+@{
+ int ival;
+ std::string* sval;
+@}
+%token <ival> NUMBER;
+%token <sval> STRING;
+@end example
+
+@noindent
+write
+
+@example
+%token <int> NUMBER;
+%token <std::string> STRING;
+@end example
+
+@code{STRING} is no longer a pointer, which should fairly simplify the user
+actions in the grammar and in the scanner (in particular the memory
+management).
+
+Since C++ features destructors, and since it is customary to specialize
+@code{operator<<} to support uniform printing of values, variants also
+typically simplify Bison printers and destructors.
+
+Variants are stricter than unions. When based on unions, you may play any
+dirty game with @code{yylval}, say storing an @code{int}, reading a
+@code{char*}, and then storing a @code{double} in it. This is no longer
+possible with variants: they must be initialized, then assigned to, and
+eventually, destroyed.
+
+@deftypemethod {semantic_type} {T&} build<T> ()
+Initialize, but leave empty. Returns the address where the actual value may
+be stored. Requires that the variant was not initialized yet.
+@end deftypemethod
+
+@deftypemethod {semantic_type} {T&} build<T> (const T& @var{t})
+Initialize, and copy-construct from @var{t}.
+@end deftypemethod
+
+
+@strong{Warning}: We do not use Boost.Variant, for two reasons. First, it
+appeared unacceptable to require Boost on the user's machine (i.e., the
+machine on which the generated parser will be compiled, not the machine on
+which @command{bison} was run). Second, for each possible semantic value,
+Boost.Variant not only stores the value, but also a tag specifying its
+type. But the parser already ``knows'' the type of the semantic value, so
+that would be duplicating the information.
+
+Therefore we developed light-weight variants whose type tag is external (so
+they are really like @code{unions} for C++ actually). But our code is much
+less mature that Boost.Variant. So there is a number of limitations in
+(the current implementation of) variants:
+@itemize
+@item
+Alignment must be enforced: values should be aligned in memory according to
+the most demanding type. Computing the smallest alignment possible requires
+meta-programming techniques that are not currently implemented in Bison, and
+therefore, since, as far as we know, @code{double} is the most demanding
+type on all platforms, alignments are enforced for @code{double} whatever
+types are actually used. This may waste space in some cases.
+
+@item
+Our implementation is not conforming with strict aliasing rules. Alias
+analysis is a technique used in optimizing compilers to detect when two
+pointers are disjoint (they cannot ``meet''). Our implementation breaks
+some of the rules that G++ 4.4 uses in its alias analysis, so @emph{strict
+alias analysis must be disabled}. Use the option
+@option{-fno-strict-aliasing} to compile the generated parser.
+
+@item
+There might be portability issues we are not aware of.
+@end itemize
+
+As far as we know, these limitations @emph{can} be alleviated. All it takes
+is some time and/or some talented C++ hacker willing to contribute to Bison.
@node C++ Location Values
@subsection C++ Location Values
@defcv {Type} {parser} {semantic_type}
@defcvx {Type} {parser} {location_type}
-The types for semantics value and locations.
+The types for semantic values and locations (if enabled).
@end defcv
@defcv {Type} {parser} {token}
(@pxref{Calc++ Scanner}).
@end defcv
+@defcv {Type} {parser} {syntax_error}
+This class derives from @code{std::runtime_error}. Throw instances of it
+from the scanner or from the user actions to raise parse errors. This is
+equivalent with first
+invoking @code{error} to report the location and message of the syntax
+error, and then to invoke @code{YYERROR} to enter the error-recovery mode.
+But contrary to @code{YYERROR} which can only be invoked from user actions
+(i.e., written in the action itself), the exception can be thrown from
+function invoked from the user action.
+@end defcv
+
@deftypemethod {parser} {} parser (@var{type1} @var{arg1}, ...)
Build a new parser object. There are no arguments by default, unless
@samp{%parse-param @{@var{type1} @var{arg1}@}} was used.
@end deftypemethod
+@deftypemethod {syntax_error} {} syntax_error (const location_type& @var{l}, const std::string& @var{m})
+@deftypemethodx {syntax_error} {} syntax_error (const std::string& @var{m})
+Instantiate a syntax-error exception.
+@end deftypemethod
+
@deftypemethod {parser} {int} parse ()
Run the syntactic analysis, and return 0 on success, 1 otherwise.
@end deftypemethod
@end deftypemethod
@deftypemethod {parser} {void} error (const location_type& @var{l}, const std::string& @var{m})
+@deftypemethodx {parser} {void} error (const std::string& @var{m})
The definition for this member function must be supplied by the user:
the parser uses it to report a parser error occurring at @var{l},
-described by @var{m}.
+described by @var{m}. If location tracking is not enabled, the second
+signature is used.
@end deftypemethod
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{%define api.pure} directive. Therefore the interface is as follows.
+@samp{%define api.pure} directive. The actual interface with @code{yylex}
+depends whether you use unions, or variants.
+
+@menu
+* Split Symbols:: Passing symbols as two/three components
+* Complete Symbols:: Making symbols a whole
+@end menu
+
+@node Split Symbols
+@subsubsection Split Symbols
+
+Therefore the interface is as follows.
@deftypemethod {parser} {int} yylex (semantic_type* @var{yylval}, location_type* @var{yylloc}, @var{type1} @var{arg1}, ...)
-Return the next token. Its type is the return value, its semantic
-value and location being @var{yylval} and @var{yylloc}. Invocations of
+@deftypemethodx {parser} {int} yylex (semantic_type* @var{yylval}, @var{type1} @var{arg1}, ...)
+Return the next token. Its type is the return value, its semantic value and
+location (if enabled) being @var{yylval} and @var{yylloc}. Invocations of
@samp{%lex-param @{@var{type1} @var{arg1}@}} yield additional arguments.
@end deftypemethod
+Note that when using variants, the interface for @code{yylex} is the same,
+but @code{yylval} is handled differently.
+
+Regular union-based code in Lex scanner typically look like:
+
+@example
+[0-9]+ @{
+ yylval.ival = text_to_int (yytext);
+ return yy::parser::INTEGER;
+ @}
+[a-z]+ @{
+ yylval.sval = new std::string (yytext);
+ return yy::parser::IDENTIFIER;
+ @}
+@end example
+
+Using variants, @code{yylval} is already constructed, but it is not
+initialized. So the code would look like:
+
+@example
+[0-9]+ @{
+ yylval.build<int>() = text_to_int (yytext);
+ return yy::parser::INTEGER;
+ @}
+[a-z]+ @{
+ yylval.build<std::string> = yytext;
+ return yy::parser::IDENTIFIER;
+ @}
+@end example
+
+@noindent
+or
+
+@example
+[0-9]+ @{
+ yylval.build(text_to_int (yytext));
+ return yy::parser::INTEGER;
+ @}
+[a-z]+ @{
+ yylval.build(yytext);
+ return yy::parser::IDENTIFIER;
+ @}
+@end example
+
+
+@node Complete Symbols
+@subsubsection Complete Symbols
+
+If you specified both @code{%define variant} and @code{%define lex_symbol},
+the @code{parser} class also defines the class @code{parser::symbol_type}
+which defines a @emph{complete} symbol, aggregating its type (i.e., the
+traditional value returned by @code{yylex}), its semantic value (i.e., the
+value passed in @code{yylval}, and possibly its location (@code{yylloc}).
+
+@deftypemethod {symbol_type} {} symbol_type (token_type @var{type}, const semantic_type& @var{value}, const location_type& @var{location})
+Build a complete terminal symbol which token type is @var{type}, and which
+semantic value is @var{value}. If location tracking is enabled, also pass
+the @var{location}.
+@end deftypemethod
+
+This interface is low-level and should not be used for two reasons. First,
+it is inconvenient, as you still have to build the semantic value, which is
+a variant, and second, because consistency is not enforced: as with unions,
+it is still possible to give an integer as semantic value for a string.
+
+So for each token type, Bison generates named constructors as follows.
+
+@deftypemethod {symbol_type} {} make_@var{token} (const @var{value_type}& @var{value}, const location_type& @var{location})
+@deftypemethodx {symbol_type} {} make_@var{token} (const location_type& @var{location})
+Build a complete terminal symbol for the token type @var{token} (not
+including the @code{api.tokens.prefix}) whose possible semantic value is
+@var{value} of adequate @var{value_type}. If location tracking is enabled,
+also pass the @var{location}.
+@end deftypemethod
+
+For instance, given the following declarations:
+
+@example
+%define api.tokens.prefix "TOK_"
+%token <std::string> IDENTIFIER;
+%token <int> INTEGER;
+%token COLON;
+@end example
+
+@noindent
+Bison generates the following functions:
+
+@example
+symbol_type make_IDENTIFIER(const std::string& v,
+ const location_type& l);
+symbol_type make_INTEGER(const int& v,
+ const location_type& loc);
+symbol_type make_COLON(const location_type& loc);
+@end example
+
+@noindent
+which should be used in a Lex-scanner as follows.
+
+@example
+[0-9]+ return yy::parser::make_INTEGER(text_to_int (yytext), loc);
+[a-z]+ return yy::parser::make_IDENTIFIER(yytext, loc);
+":" return yy::parser::make_COLON(loc);
+@end example
+
+Tokens that do not have an identifier are not accessible: you cannot simply
+use characters such as @code{':'}, they must be declared with @code{%token}.
@node A Complete C++ Example
@subsection A Complete C++ Example
This section demonstrates the use of a C++ parser with a simple but
complete example. This example should be available on your system,
-ready to compile, in the directory @dfn{../bison/examples/calc++}. It
+ready to compile, in the directory @dfn{.../bison/examples/calc++}. It
focuses on the use of Bison, therefore the design of the various C++
classes is very naive: no accessors, no encapsulation of members etc.
We will use a Lex scanner, and more precisely, a Flex scanner, to
-demonstrate the various interaction. A hand written scanner is
+demonstrate the various interactions. A hand-written scanner is
actually easier to interface with.
@menu
@comment file: calc++-driver.hh
@example
// Tell Flex the lexer's prototype ...
-# define YY_DECL \
- yy::calcxx_parser::token_type \
- yylex (yy::calcxx_parser::semantic_type* yylval, \
- yy::calcxx_parser::location_type* yylloc, \
- calcxx_driver& driver)
+# define YY_DECL \
+ yy::calcxx_parser::symbol_type yylex (calcxx_driver& driver)
// ... and declare it for the parser's sake.
YY_DECL;
@end example
@end example
@noindent
-To encapsulate the coordination with the Flex scanner, it is useful to
-have two members function to open and close the scanning phase.
+To encapsulate the coordination with the Flex scanner, it is useful to have
+member functions to open and close the scanning phase.
@comment file: calc++-driver.hh
@example
@comment file: calc++-driver.hh
@example
- // Run the parser. Return 0 on success.
+ // Run the parser on file F.
+ // Return 0 on success.
int parse (const std::string& f);
+ // The name of the file being parsed.
+ // Used later to pass the file name to the location tracker.
std::string file;
+ // Whether parser traces should be generated.
bool trace_parsing;
@end example
%define parser_class_name "calcxx_parser"
@end example
+@noindent
+@findex %define variant
+@findex %define lex_symbol
+This example will use genuine C++ objects as semantic values, therefore, we
+require the variant-based interface. To make sure we properly use it, we
+enable assertions. To fully benefit from type-safety and more natural
+definition of ``symbol'', we enable @code{lex_symbol}.
+
+@comment file: calc++-parser.yy
+@example
+%define variant
+%define parse.assert
+%define lex_symbol
+@end example
+
@noindent
@findex %code requires
-Then come the declarations/inclusions needed to define the
-@code{%union}. Because the parser uses the parsing driver and
-reciprocally, both cannot include the header of the other. Because the
+Then come the declarations/inclusions needed by the semantic values.
+Because the parser uses the parsing driver and reciprocally, both would like
+to include the header of the other, which is, of course, insane. This
+mutual dependency will be broken using forward declarations. Because the
driver's header needs detailed knowledge about the parser class (in
-particular its inner types), it is the parser's header which will simply
-use a forward declaration of the driver.
-@xref{%code Summary}.
+particular its inner types), it is the parser's header which will use a
+forward declaration of the driver. @xref{%code Summary}.
@comment file: calc++-parser.yy
@example
-%code requires @{
+%code requires
+@{
# include <string>
class calcxx_driver;
@}
@comment file: calc++-parser.yy
@example
// The parsing context.
-%parse-param @{ calcxx_driver& driver @}
-%lex-param @{ calcxx_driver& driver @}
+%param @{ calcxx_driver& driver @}
@end example
@noindent
-Then we request the location tracking feature, and initialize the
+Then we request location tracking, and initialize the
first location's file name. Afterward new locations are computed
relatively to the previous locations: the file name will be
-automatically propagated.
+propagated.
@comment file: calc++-parser.yy
@example
@end example
@noindent
-Use the two following directives to enable parser tracing and verbose error
+Use the following two directives to enable parser tracing and verbose error
messages. However, verbose error messages can contain incorrect information
(@pxref{LAC}).
@comment file: calc++-parser.yy
@example
-%debug
-%error-verbose
-@end example
-
-@noindent
-Semantic values cannot use ``real'' objects, but only pointers to
-them.
-
-@comment file: calc++-parser.yy
-@example
-// Symbols.
-%union
-@{
- int ival;
- std::string *sval;
-@};
+%define parse.trace
+%define parse.error verbose
@end example
@noindent
@comment file: calc++-parser.yy
@example
-%code @{
+%code
+@{
# include "calc++-driver.hh"
@}
@end example
@noindent
The token numbered as 0 corresponds to end of file; the following line
-allows for nicer error messages referring to ``end of file'' instead
-of ``$end''. Similarly user friendly named are provided for each
-symbol. Note that the tokens names are prefixed by @code{TOKEN_} to
-avoid name clashes.
+allows for nicer error messages referring to ``end of file'' instead of
+``$end''. Similarly user friendly names are provided for each symbol. To
+avoid name clashes in the generated files (@pxref{Calc++ Scanner}), prefix
+tokens with @code{TOK_} (@pxref{%define Summary,,api.tokens.prefix}).
@comment file: calc++-parser.yy
@example
-%token END 0 "end of file"
-%token ASSIGN ":="
-%token <sval> IDENTIFIER "identifier"
-%token <ival> NUMBER "number"
-%type <ival> exp
+%define api.tokens.prefix "TOK_"
+%token
+ END 0 "end of file"
+ ASSIGN ":="
+ MINUS "-"
+ PLUS "+"
+ STAR "*"
+ SLASH "/"
+ LPAREN "("
+ RPAREN ")"
+;
@end example
@noindent
-To enable memory deallocation during error recovery, use
-@code{%destructor}.
+Since we use variant-based semantic values, @code{%union} is not used, and
+both @code{%type} and @code{%token} expect genuine types, as opposed to type
+tags.
-@c FIXME: Document %printer, and mention that it takes a braced-code operand.
@comment file: calc++-parser.yy
@example
-%printer @{ yyoutput << *$$; @} "identifier"
-%destructor @{ delete $$; @} "identifier"
+%token <std::string> IDENTIFIER "identifier"
+%token <int> NUMBER "number"
+%type <int> exp
+@end example
+
+@noindent
+No @code{%destructor} is needed to enable memory deallocation during error
+recovery; the memory, for strings for instance, will be reclaimed by the
+regular destructors. All the values are printed using their
+@code{operator<<}.
-%printer @{ yyoutput << $$; @} <ival>
+@c FIXME: Document %printer, and mention that it takes a braced-code operand.
+@comment file: calc++-parser.yy
+@example
+%printer @{ yyoutput << $$; @} <*>;
@end example
@noindent
-The grammar itself is straightforward.
+The grammar itself is straightforward (@pxref{Location Tracking Calc, ,
+Location Tracking Calculator: @code{ltcalc}}).
@comment file: calc++-parser.yy
@example
| assignments assignment @{@};
assignment:
- "identifier" ":=" exp
- @{ driver.variables[*$1] = $3; delete $1; @};
-
-%left '+' '-';
-%left '*' '/';
-exp: exp '+' exp @{ $$ = $1 + $3; @}
- | exp '-' exp @{ $$ = $1 - $3; @}
- | exp '*' exp @{ $$ = $1 * $3; @}
- | exp '/' exp @{ $$ = $1 / $3; @}
- | "identifier" @{ $$ = driver.variables[*$1]; delete $1; @}
- | "number" @{ $$ = $1; @};
+ "identifier" ":=" exp @{ driver.variables[$1] = $3; @};
+
+%left "+" "-";
+%left "*" "/";
+exp:
+ exp "+" exp @{ $$ = $1 + $3; @}
+| exp "-" exp @{ $$ = $1 - $3; @}
+| exp "*" exp @{ $$ = $1 * $3; @}
+| exp "/" exp @{ $$ = $1 / $3; @}
+| "(" exp ")" @{ std::swap ($$, $2); @}
+| "identifier" @{ $$ = driver.variables[$1]; @}
+| "number" @{ std::swap ($$, $1); @};
%%
@end example
@comment file: calc++-parser.yy
@example
void
-yy::calcxx_parser::error (const yy::calcxx_parser::location_type& l,
+yy::calcxx_parser::error (const location_type& l,
const std::string& m)
@{
driver.error (l, m);
@comment file: calc++-scanner.ll
@example
%@{ /* -*- C++ -*- */
-# include <cstdlib>
# include <cerrno>
# include <climits>
+# include <cstdlib>
# include <string>
# include "calc++-driver.hh"
# include "calc++-parser.hh"
-/* Work around an incompatibility in flex (at least versions
- 2.5.31 through 2.5.33): it generates code that does
- not conform to C89. See Debian bug 333231
- <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=333231>. */
+// Work around an incompatibility in flex (at least versions
+// 2.5.31 through 2.5.33): it generates code that does
+// not conform to C89. See Debian bug 333231
+// <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=333231>.
# undef yywrap
# define yywrap() 1
-/* By default yylex returns int, we use token_type.
- Unfortunately yyterminate by default returns 0, which is
- not of token_type. */
-#define yyterminate() return token::END
+// The location of the current token.
+static yy::location loc;
%@}
@end example
Because there is no @code{#include}-like feature we don't need
@code{yywrap}, we don't need @code{unput} either, and we parse an
actual file, this is not an interactive session with the user.
-Finally we enable the scanner tracing features.
+Finally, we enable scanner tracing.
@comment file: calc++-scanner.ll
@example
@noindent
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
+position. Then when a pattern is matched, its width is added to the end
+column. When matching ends of lines, the end
cursor is adjusted, and each time blanks are matched, the begin cursor
is moved onto the end cursor to effectively ignore the blanks
preceding tokens. Comments would be treated equally.
@example
@group
%@{
-# define YY_USER_ACTION yylloc->columns (yyleng);
+ // Code run each time a pattern is matched.
+ # define YY_USER_ACTION loc.columns (yyleng);
%@}
@end group
%%
+@group
%@{
- yylloc->step ();
+ // Code run each time yylex is called.
+ loc.step ();
%@}
-@{blank@}+ yylloc->step ();
-[\n]+ yylloc->lines (yyleng); yylloc->step ();
+@end group
+@{blank@}+ loc.step ();
+[\n]+ loc.lines (yyleng); loc.step ();
@end example
@noindent
-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 instance.
+The rules are simple. The driver is used to report errors.
@comment file: calc++-scanner.ll
@example
-%@{
- typedef yy::calcxx_parser::token token;
-%@}
- /* Convert ints to the actual type of tokens. */
-[-+*/] return yy::calcxx_parser::token_type (yytext[0]);
-":=" return token::ASSIGN;
+"-" return yy::calcxx_parser::make_MINUS(loc);
+"+" return yy::calcxx_parser::make_PLUS(loc);
+"*" return yy::calcxx_parser::make_STAR(loc);
+"/" return yy::calcxx_parser::make_SLASH(loc);
+"(" return yy::calcxx_parser::make_LPAREN(loc);
+")" return yy::calcxx_parser::make_RPAREN(loc);
+":=" return yy::calcxx_parser::make_ASSIGN(loc);
+
+@group
@{int@} @{
errno = 0;
long n = strtol (yytext, NULL, 10);
if (! (INT_MIN <= n && n <= INT_MAX && errno != ERANGE))
- driver.error (*yylloc, "integer is out of range");
- yylval->ival = n;
- return token::NUMBER;
+ driver.error (loc, "integer is out of range");
+ return yy::calcxx_parser::make_NUMBER(n, loc);
@}
-@{id@} yylval->sval = new std::string (yytext); return token::IDENTIFIER;
-. driver.error (*yylloc, "invalid character");
+@end group
+@{id@} return yy::calcxx_parser::make_IDENTIFIER(yytext, loc);
+. driver.error (loc, "invalid character");
+<<EOF>> return yy::calcxx_parser::make_END(loc);
%%
@end example
@noindent
-Finally, because the scanner related driver's member function depend
+Finally, because the scanner-related driver's member-functions depend
on the scanner's data, it is simpler to implement them in this file.
@comment file: calc++-scanner.ll
int
main (int argc, char *argv[])
@{
+ int res = 0;
calcxx_driver driver;
for (int i = 1; i < argc; ++i)
if (argv[i] == std::string ("-p"))
driver.trace_scanning = true;
else if (!driver.parse (argv[i]))
std::cout << driver.result << std::endl;
+ else
+ res = 1;
+ return res;
@}
@end group
@end example
Contrary to C parsers, Java parsers do not use global variables; the
state of the parser is always local to an instance of the parser class.
Therefore, all Java parsers are ``pure'', and the @code{%pure-parser}
-and @code{%define api.pure} directives does not do anything when used in
+and @samp{%define api.pure} directives does not do anything when used in
Java.
Push parsers are currently unsupported in Java and @code{%define
@code{%defines} directive or the @option{-d}/@option{--defines} options.
@c FIXME: Possible code change.
-Currently, support for debugging and verbose errors are always compiled
-in. Thus the @code{%debug} and @code{%token-table} directives and the
+Currently, support for tracing is always compiled
+in. Thus the @samp{%define parse.trace} and @samp{%token-table}
+directives and the
@option{-t}/@option{--debug} and @option{-k}/@option{--token-table}
options have no effect. This may change in the future to eliminate
-unused code in the generated parser, so use @code{%debug} and
-@code{%verbose-error} explicitly if needed. Also, in the future the
+unused code in the generated parser, so use @samp{%define parse.trace}
+explicitly
+if needed. Also, in the future the
@code{%token-table} directive might enable a public interface to
access the token names and codes.
+Getting a ``code too large'' error from the Java compiler means the code
+hit the 64KB bytecode per method limitation of the Java class file.
+Try reducing the amount of code in actions and static initializers;
+otherwise, report a bug so that the parser skeleton will be improved.
+
+
@node Java Semantic Values
@subsection Java Semantic Values
@c - No %union, specify type in %type/%token.
By default, the semantic stack is declared to have @code{Object} members,
which means that the class types you specify can be of any class.
To improve the type safety of the parser, you can declare the common
-superclass of all the semantic values using the @code{%define stype}
+superclass of all the semantic values using the @samp{%define stype}
directive. For example, after the following declaration:
@example
defines a class representing a @dfn{location}, a range composed of a pair of
positions (possibly spanning several files). The location class is an inner
class of the parser; the name is @code{Location} by default, and may also be
-renamed using @code{%define location_type "@var{class-name}"}.
+renamed using @samp{%define location_type "@var{class-name}"}.
The location class treats the position as a completely opaque value.
By default, the class name is @code{Position}, but this can be changed
-with @code{%define position_type "@var{class-name}"}. This class must
+with @samp{%define position_type "@var{class-name}"}. This class must
be supplied by the user.
The name of the generated parser class defaults to @code{YYParser}. The
@code{YY} prefix may be changed using the @code{%name-prefix} directive
or the @option{-p}/@option{--name-prefix} option. Alternatively, use
-@code{%define parser_class_name "@var{name}"} to give a custom name to
+@samp{%define parser_class_name "@var{name}"} to give a custom name to
the class. The interface of this class is detailed below.
By default, the parser class has package visibility. A declaration
-@code{%define public} will change to public visibility. Remember that,
+@samp{%define public} will change to public visibility. Remember that,
according to the Java language specification, the name of the @file{.java}
file should match the name of the class in this case. Similarly, you can
use @code{abstract}, @code{final} and @code{strictfp} with the
@code{%define} declaration to add other modifiers to the parser class.
+A single @samp{%define annotations "@var{annotations}"} directive can
+be used to add any number of annotations to the parser class.
The Java package name of the parser class can be specified using the
-@code{%define package} directive. The superclass and the implemented
+@samp{%define package} directive. The superclass and the implemented
interfaces of the parser class can be specified with the @code{%define
-extends} and @code{%define implements} directives.
+extends} and @samp{%define implements} directives.
The parser class defines an inner class, @code{Location}, that is used
for location tracking (see @ref{Java Location Values}), and a inner
below, all the other members and fields are preceded with a @code{yy} or
@code{YY} prefix to avoid clashes with user code.
-@c FIXME: The following constants and variables are still undocumented:
-@c @code{bisonVersion}, @code{bisonSkeleton} and @code{errorVerbose}.
-
The parser class can be extended using the @code{%parse-param}
directive. Each occurrence of the directive will add a @code{protected
final} field to the parser class, and an argument to its constructor,
which initialize them automatically.
-Token names defined by @code{%token} and the predefined @code{EOF} token
-name are added as constant fields to the parser class.
-
@deftypeop {Constructor} {YYParser} {} YYParser (@var{lex_param}, @dots{}, @var{parse_param}, @dots{})
Build a new parser object with embedded @code{%code lexer}. There are
-no parameters, unless @code{%parse-param}s and/or @code{%lex-param}s are
-used.
+no parameters, unless @code{%param}s and/or @code{%parse-param}s and/or
+@code{%lex-param}s are used.
+
+Use @code{%code init} for code added to the start of the constructor
+body. This is especially useful to initialize superclasses. Use
+@samp{%define init_throws} to specify any uncaught exceptions.
@end deftypeop
@deftypeop {Constructor} {YYParser} {} YYParser (Lexer @var{lexer}, @var{parse_param}, @dots{})
Build a new parser object using the specified scanner. There are no
-additional parameters unless @code{%parse-param}s are used.
+additional parameters unless @code{%param}s and/or @code{%parse-param}s are
+used.
If the scanner is defined by @code{%code lexer}, this constructor is
declared @code{protected} and is called automatically with a scanner
-created with the correct @code{%lex-param}s.
+created with the correct @code{%param}s and/or @code{%lex-param}s.
+
+Use @code{%code init} for code added to the start of the constructor
+body. This is especially useful to initialize superclasses. Use
+@samp{%define init_throws} to specify any uncaught exceptions.
@end deftypeop
@deftypemethod {YYParser} {boolean} parse ()
@code{false} otherwise.
@end deftypemethod
+@deftypemethod {YYParser} {boolean} getErrorVerbose ()
+@deftypemethodx {YYParser} {void} setErrorVerbose (boolean @var{verbose})
+Get or set the option to produce verbose error messages. These are only
+available with @samp{%define parse.error verbose}, which also turns on
+verbose error messages.
+@end deftypemethod
+
+@deftypemethod {YYParser} {void} yyerror (String @var{msg})
+@deftypemethodx {YYParser} {void} yyerror (Position @var{pos}, String @var{msg})
+@deftypemethodx {YYParser} {void} yyerror (Location @var{loc}, String @var{msg})
+Print an error message using the @code{yyerror} method of the scanner
+instance in use. The @code{Location} and @code{Position} parameters are
+available only if location tracking is active.
+@end deftypemethod
+
@deftypemethod {YYParser} {boolean} recovering ()
During the syntactic analysis, return @code{true} if recovering
from a syntax error.
or nonzero, full tracing.
@end deftypemethod
+@deftypecv {Constant} {YYParser} {String} {bisonVersion}
+@deftypecvx {Constant} {YYParser} {String} {bisonSkeleton}
+Identify the Bison version and skeleton used to generate this parser.
+@end deftypecv
+
@node Java Scanner Interface
@subsection Java Scanner Interface
There are two possible ways to interface a Bison-generated Java parser
with a scanner: the scanner may be defined by @code{%code lexer}, or
defined elsewhere. In either case, the scanner has to implement the
-@code{Lexer} inner interface of the parser class.
+@code{Lexer} inner interface of the parser class. This interface also
+contain constants for all user-defined token names and the predefined
+@code{EOF} token.
In the first case, the body of the scanner class is placed in
@code{%code lexer} blocks. If you want to pass parameters from the
@deftypemethod {Lexer} {void} yyerror (Location @var{loc}, String @var{msg})
This method is defined by the user to emit an error message. The first
parameter is omitted if location tracking is not active. Its type can be
-changed using @code{%define location_type "@var{class-name}".}
+changed using @samp{%define location_type "@var{class-name}".}
@end deftypemethod
@deftypemethod {Lexer} {int} yylex ()
value and location are saved and returned by the their methods in the
interface.
-Use @code{%define lex_throws} to specify any uncaught exceptions.
+Use @samp{%define lex_throws} to specify any uncaught exceptions.
Default is @code{java.io.IOException}.
@end deftypemethod
@code{yylex} returned, and the first position beyond it. These
methods are not needed unless location tracking is active.
-The return type can be changed using @code{%define position_type
+The return type can be changed using @samp{%define position_type
"@var{class-name}".}
@end deftypemethod
@deftypemethod {Lexer} {Object} getLVal ()
Return the semantic value of the last token that yylex returned.
-The return type can be changed using @code{%define stype
+The return type can be changed using @samp{%define stype
"@var{class-name}".}
@end deftypemethod
The following special constructs can be uses in Java actions.
Other analogous C action features are currently unavailable for Java.
-Use @code{%define throws} to specify any uncaught exceptions from parser
+Use @samp{%define throws} to specify any uncaught exceptions from parser
actions, and initial actions specified by @code{%initial-action}.
@defvar $@var{n}
@defvar $$
The semantic value for the grouping made by the current rule. As a
value, this is in the base type (@code{Object} or as specified by
-@code{%define stype}) as in not cast to the declared subtype because
+@samp{%define stype}) as in not cast to the declared subtype because
casts are not allowed on the left-hand side of Java assignments.
Use an explicit Java cast if the correct subtype is needed.
@xref{Java Semantic Values}.
@xref{Java Location Values}.
@end defvar
- @deffn {Statement} {return YYABORT;}
+ @deftypefn {Statement} return YYABORT @code{;}
Return immediately from the parser, indicating failure.
@xref{Java Parser Interface}.
- @end deffn
+ @end deftypefn
- @deffn {Statement} {return YYACCEPT;}
+ @deftypefn {Statement} return YYACCEPT @code{;}
Return immediately from the parser, indicating success.
@xref{Java Parser Interface}.
- @end deffn
+ @end deftypefn
- @deffn {Statement} {return YYERROR;}
- Start error recovery without printing an error message.
+ @deftypefn {Statement} {return} YYERROR @code{;}
+ Start error recovery (without printing an error message).
@xref{Error Recovery}.
- @end deffn
+ @end deftypefn
@deftypefn {Function} {boolean} recovering ()
Return whether error recovery is being done. In this state, the parser
@xref{Error Recovery}.
@end deftypefn
-@deftypefn {Function} {protected void} yyerror (String msg)
-@deftypefnx {Function} {protected void} yyerror (Position pos, String msg)
-@deftypefnx {Function} {protected void} yyerror (Location loc, String msg)
+@deftypefn {Function} {void} yyerror (String @var{msg})
+@deftypefnx {Function} {void} yyerror (Position @var{loc}, String @var{msg})
+@deftypefnx {Function} {void} yyerror (Location @var{loc}, String @var{msg})
Print an error message using the @code{yyerror} method of the scanner
-instance in use.
+instance in use. The @code{Location} and @code{Position} parameters are
+available only if location tracking is active.
@end deftypefn
@item @code{%code imports}
blocks are placed at the beginning of the Java source code. They may
include copyright notices. For a @code{package} declarations, it is
-suggested to use @code{%define package} instead.
+suggested to use @samp{%define package} instead.
@item unqualified @code{%code}
blocks are placed inside the parser class.
@deffn {Directive} %name-prefix "@var{prefix}"
The prefix of the parser class name @code{@var{prefix}Parser} if
-@code{%define parser_class_name} is not used. Default is @code{YY}.
+@samp{%define parser_class_name} is not used. Default is @code{YY}.
@xref{Java Bison Interface}.
@end deffn
@xref{Java Differences}.
@end deffn
+@deffn {Directive} {%code init} @{ @var{code} @dots{} @}
+Code inserted at the beginning of the parser constructor body.
+@xref{Java Parser Interface}.
+@end deffn
+
@deffn {Directive} {%code lexer} @{ @var{code} @dots{} @}
Code added to the body of a inner lexer class within the parser class.
@xref{Java Scanner Interface}.
@end deffn
@deffn {Directive} %@{ @var{code} @dots{} %@}
-Not supported. Use @code{%code import} instead.
+Not supported. Use @code{%code imports} instead.
@xref{Java Differences}.
@end deffn
@xref{Java Bison Interface}.
@end deffn
+@deffn {Directive} {%define annotations} "@var{annotations}"
+The Java annotations for the parser class. Default is none.
+@xref{Java Bison Interface}.
+@end deffn
+
@deffn {Directive} {%define extends} "@var{superclass}"
The superclass of the parser class. Default is none.
@xref{Java Bison Interface}.
@xref{Java Bison Interface}.
@end deffn
+@deffn {Directive} {%define init_throws} "@var{exceptions}"
+The exceptions thrown by @code{%code init} from the parser class
+constructor. Default is none.
+@xref{Java Parser Interface}.
+@end deffn
+
@deffn {Directive} {%define lex_throws} "@var{exceptions}"
The exceptions thrown by the @code{yylex} method of the lexer, a
comma-separated list. Default is @code{java.io.IOException}.
Grammar}.
@end deffn
+@deffn {Directive} %?@{@var{expression}@}
+Predicate actions. This is a type of action clause that may appear in
+rules. The expression is evaluated, and if false, causes a syntax error. In
+GLR parsers during nondeterministic operation,
+this silently causes an alternative parse to die. During deterministic
+operation, it is the same as the effect of YYERROR.
+@xref{Semantic Predicates}.
+
+This feature is experimental.
+More user feedback will help to determine whether it should become a permanent
+feature.
+@end deffn
+
@deffn {Construct} /*@dots{}*/
Comment delimiters, as in C.
@end deffn
@end deffn
@deffn {Directive} %error-verbose
-Bison declaration to request verbose, specific error message strings
-when @code{yyerror} is called. @xref{Error Reporting}.
+An obsolete directive standing for @samp{%define parse.error verbose}
+(@pxref{Error Reporting, ,The Error Reporting Function @code{yyerror}}).
@end deffn
@deffn {Directive} %file-prefix "@var{prefix}"
@end deffn
@deffn {Directive} %left
-Bison declaration to assign left associativity to token(s).
+Bison declaration to assign precedence and left associativity to token(s).
@xref{Precedence Decl, ,Operator Precedence}.
@end deffn
-@deffn {Directive} %lex-param @{@var{argument-declaration}@}
-Bison declaration to specifying an additional parameter that
+@deffn {Directive} %lex-param @{@var{argument-declaration}@} @dots{}
+Bison declaration to specifying additional arguments that
@code{yylex} should accept. @xref{Pure Calling,, Calling Conventions
for Pure Parsers}.
@end deffn
@end deffn
@deffn {Directive} %nonassoc
-Bison declaration to assign nonassociativity to token(s).
+Bison declaration to assign precedence and nonassociativity to token(s).
@xref{Precedence Decl, ,Operator Precedence}.
@end deffn
@xref{Decl Summary}.
@end deffn
-@deffn {Directive} %parse-param @{@var{argument-declaration}@}
-Bison declaration to specifying an additional parameter that
-@code{yyparse} should accept. @xref{Parser Function,, The Parser
-Function @code{yyparse}}.
+@deffn {Directive} %param @{@var{argument-declaration}@} @dots{}
+Bison declaration to specify additional arguments that both
+@code{yylex} and @code{yyparse} should accept. @xref{Parser Function,, The
+Parser Function @code{yyparse}}.
+@end deffn
+
+@deffn {Directive} %parse-param @{@var{argument-declaration}@} @dots{}
+Bison declaration to specify additional arguments that @code{yyparse}
+should accept. @xref{Parser Function,, The Parser Function @code{yyparse}}.
@end deffn
@deffn {Directive} %prec
@xref{Contextual Precedence, ,Context-Dependent Precedence}.
@end deffn
+@deffn {Directive} %precedence
+Bison declaration to assign precedence to token(s), but no associativity
+@xref{Precedence Decl, ,Operator Precedence}.
+@end deffn
+
@deffn {Directive} %pure-parser
-Deprecated version of @code{%define api.pure} (@pxref{%define
+Deprecated version of @samp{%define api.pure} (@pxref{%define
Summary,,api.pure}), for which Bison is more careful to warn about
unreasonable usage.
@end deffn
@end deffn
@deffn {Directive} %right
-Bison declaration to assign right associativity to token(s).
+Bison declaration to assign precedence and right associativity to token(s).
@xref{Precedence Decl, ,Operator Precedence}.
@end deffn
@end deffn
@deffn {Macro} YYERROR
- Macro to pretend that a syntax error has just been detected: call
- @code{yyerror} and then perform normal error recovery if possible
- (@pxref{Error Recovery}), or (if recovery is impossible) make
- @code{yyparse} return 1. @xref{Error Recovery}.
+ Cause an immediate syntax error. This statement initiates error
+ recovery just as if the parser itself had detected an error; however, it
+ does not call @code{yyerror}, and does not print any message. If you
+ want to print an error message, call @code{yyerror} explicitly before
+ the @samp{YYERROR;} statement. @xref{Error Recovery}.
For Java parsers, this functionality is invoked using @code{return YYERROR;}
instead.
@deffn {Function} yyerror
User-supplied function to be called by @code{yyparse} on error.
-@xref{Error Reporting, ,The Error
-Reporting Function @code{yyerror}}.
+@xref{Error Reporting, ,The Error Reporting Function @code{yyerror}}.
@end deffn
@deffn {Macro} YYERROR_VERBOSE
-An obsolete macro that you define with @code{#define} in the prologue
-to request verbose, specific error message strings
-when @code{yyerror} is called. It doesn't matter what definition you
-use for @code{YYERROR_VERBOSE}, just whether you define it. Using
-@code{%error-verbose} is preferred. @xref{Error Reporting}.
+An obsolete macro used in the @file{yacc.c} skeleton, that you define
+with @code{#define} in the prologue to request verbose, specific error
+message strings when @code{yyerror} is called. It doesn't matter what
+definition you use for @code{YYERROR_VERBOSE}, just whether you define
+it. Using @samp{%define parse.error verbose} is preferred
+(@pxref{Error Reporting, ,The Error Reporting Function @code{yyerror}}).
@end deffn
@deffn {Macro} YYFPRINTF
# --------------------------------------------------
# This macro works around the impossibility to define macros
# inside macros, because issuing `[$1]' is not possible in M4 :(.
-# This sucks hard, GNU M4 should really provide M5 like $$1.
+# This sucks hard, GNU M4 should really provide M5-like $$1.
m4_define([_AT_BISON_OPTION_PUSHDEFS],
[m4_if([$1$2], $[1]$[2], [],
[m4_fatal([$0: Invalid arguments: $@])])dnl
[m4_bmatch([$3], [%name-prefix ".*"],
[m4_bregexp([$3], [name-prefix "\([^"]*\)"], [\1])],
[yy])])
+m4_pushdef([AT_TOKEN_PREFIX],
+[m4_bmatch([$3], [%define api.tokens.prefix ".*"],
+ [m4_bregexp([$3], [%define api.tokens.prefix "\(.*\)"], [\1])])])
# yyerror receives the location if %location & %pure & (%glr or %parse-param).
m4_pushdef([AT_YYERROR_ARG_LOC_IF],
[AT_GLR_OR_PARAM_IF([AT_PURE_AND_LOC_IF([$1], [$2])],
- [$2])])
+ [$2])])
# yyerror always sees the locations (when activated), except if
# (yacc & pure & !param). FIXME: This is wrong. See the manual.
m4_pushdef([AT_YYERROR_SEES_LOC_IF],
[AT_LOCATION_IF([AT_YACC_IF([AT_PURE_IF([AT_PARAM_IF([$1], [$2])],
- [$1])],
- [$1])],
- [$2])])
+ [$1])],
+ [$1])],
+ [$2])])
# 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],
- [AT_SKEL_CC_IF([$1], [$2])])])
+ [AT_SKEL_CC_IF([$1], [$2])])])
AT_PURE_LEX_IF(
[m4_pushdef([AT_LOC], [(*llocp)])
m4_pushdef([AT_VAL], [(*lvalp)])
m4_pushdef([AT_LEX_FORMALS],
- [YYSTYPE *lvalp[]AT_LOCATION_IF([, YYLTYPE *llocp])])
+ [YYSTYPE *lvalp[]AT_LOCATION_IF([, YYLTYPE *llocp])])
m4_pushdef([AT_LEX_ARGS],
- [lvalp[]AT_LOCATION_IF([, llocp])])
+ [lvalp[]AT_LOCATION_IF([, llocp])])
m4_pushdef([AT_USE_LEX_ARGS],
- [(void) lvalp;AT_LOCATION_IF([(void) llocp])])
+ [(void) lvalp;AT_LOCATION_IF([(void) llocp])])
m4_pushdef([AT_LEX_PRE_FORMALS],
- [AT_LEX_FORMALS, ])
+ [AT_LEX_FORMALS, ])
m4_pushdef([AT_LEX_PRE_ARGS],
- [AT_LEX_ARGS, ])
+ [AT_LEX_ARGS, ])
],
[m4_pushdef([AT_LOC], [[(]AT_NAME_PREFIX[lloc)]])
m4_pushdef([AT_VAL], [[(]AT_NAME_PREFIX[lval)]])
[AT_LOC_PUSHDEF([begin.line], [begin.column], [end.line], [end.column])])],
[AT_LOC_PUSHDEF([first_line], [first_column], [last_line], [last_column])])
+
+AT_GLR_IF([AT_KEYWORDS([glr])])
])# _AT_BISON_OPTION_PUSHDEFS
# assume that we are linking too; this is a hack.
m4_define([AT_COMPILE],
[AT_CHECK([$CC $CFLAGS $CPPFLAGS m4_bmatch([$1], [[.]], [], [$LDFLAGS ])-o $1 m4_default([$2], [$1.c])[]m4_bmatch([$1], [[.]], [], [ $LIBS])],
- 0, [ignore], [ignore])])
+ 0, [ignore], [ignore])])
# AT_COMPILE_CXX(OUTPUT, [SOURCES = OUTPUT.cc])
# --------------------------------------------
[AT_KEYWORDS(c++)
AT_CHECK([$BISON_CXX_WORKS], 0, ignore, ignore)
AT_CHECK([$CXX $CXXFLAGS $CPPFLAGS m4_bmatch([$1], [[.]], [], [$LDFLAGS ])-o $1 m4_default([$2], [$1.cc])[]m4_bmatch([$1], [[.]], [], [ $LIBS])],
- 0, [ignore], [ignore])])
+ 0, [ignore], [ignore])])
# AT_JAVA_COMPILE(SOURCES)
# ------------------------
## Running a generated parser. ##
## ---------------------------- ##
+
# AT_PARSER_CHECK(COMMAND, EXIT-STATUS, EXPOUT, EXPERR, [PRE])
# ------------------------------------------------------------
# So that we can run `./testsuite PREPARSER='valgrind -q' for instance.
+ #
+ # Get rid of spurious messages when compiled with --coverage:
+ # +profiling:/[...]/lib/fprintf.gcda:Merge mismatch for summaries
m4_define([AT_PARSER_CHECK],
- [AT_CHECK([$5 $PREPARSER $1], [$2], [$3], [$4])])
+ [AT_CHECK([$5 $PREPARSER $1], [$2], [$3], [stderr])
+ AT_CHECK([sed >&2 -e '/^profiling:.*:Merge mismatch for summaries/d' stderr],
+ [0], [], [$4])
+ ])
+
# AT_JAVA_PARSER_CHECK(COMMAND, EXIT-STATUS, EXPOUT, EXPERR, [PRE])
# -----------------------------------------------------------------
m4_define([AT_JAVA_PARSER_CHECK],
[AT_CHECK([$5[ $SHELL ../../../javaexec.sh ]$1], [$2], [$3], [$4])])
+
# AT_TEST_TABLES_AND_PARSE(TITLE, COND-VALUE, TEST-SPEC,
# DECLS, GRAMMAR, INPUT,
# BISON-STDERR, TABLES-OR-LAST-STATE,
projects / bison.git / commitdiff
