| Index: bison/src/bison/2.4.1/bison-2.4.1-src/src/gram.h
|
| ===================================================================
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| --- bison/src/bison/2.4.1/bison-2.4.1-src/src/gram.h (revision 0)
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| +++ bison/src/bison/2.4.1/bison-2.4.1-src/src/gram.h (revision 0)
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| @@ -0,0 +1,275 @@
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| +/* Data definitions for internal representation of Bison's input.
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| +
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| + Copyright (C) 1984, 1986, 1989, 1992, 2001, 2002, 2003, 2004, 2005, 2006
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| + 2007 Free Software Foundation, Inc.
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| +
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| + This file is part of Bison, the GNU Compiler Compiler.
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| +
|
| + This program is free software: you can redistribute it and/or modify
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| + it under the terms of the GNU General Public License as published by
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| + the Free Software Foundation, either version 3 of the License, or
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| + (at your option) any later version.
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| +
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| + This program is distributed in the hope that it will be useful,
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| + but WITHOUT ANY WARRANTY; without even the implied warranty of
|
| + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| + GNU General Public License for more details.
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| +
|
| + You should have received a copy of the GNU General Public License
|
| + along with this program. If not, see <http://www.gnu.org/licenses/>. */
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| +
|
| +#ifndef GRAM_H_
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| +# define GRAM_H_
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| +
|
| +/* Representation of the grammar rules:
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| +
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| + NTOKENS is the number of tokens, and NVARS is the number of
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| + variables (nonterminals). NSYMS is the total number, ntokens +
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| + nvars.
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| +
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| + Each symbol (either token or variable) receives a symbol number.
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| + Numbers 0 to NTOKENS - 1 are for tokens, and NTOKENS to NSYMS - 1
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| + are for variables. Symbol number zero is the end-of-input token.
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| + This token is counted in ntokens. The true number of token values
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| + assigned is NTOKENS reduced by one for each alias declaration.
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| +
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| + The rules receive rule numbers 1 to NRULES in the order they are
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| + written. More precisely Bison augments the grammar with the
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| + initial rule, `$accept: START-SYMBOL $end', which is numbered 1,
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| + all the user rules are 2, 3 etc. Each time a rule number is
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| + presented to the user, we subtract 1, so *displayed* rule numbers
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| + are 0, 1, 2...
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| +
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| + Internally, we cannot use the number 0 for a rule because for
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| + instance RITEM stores both symbol (the RHS) and rule numbers: the
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| + symbols are shorts >= 0, and rule number are stored negative.
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| + Therefore 0 cannot be used, since it would be both the rule number
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| + 0, and the token $end).
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| +
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| + Actions are accessed via the rule number.
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| +
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| + The rules themselves are described by several arrays: amongst which
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| + RITEM, and RULES.
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| +
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| + RULES is an array of rules, whose members are:
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| +
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| + RULES[R].lhs -- the symbol of the left hand side of rule R.
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| +
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| + RULES[R].rhs -- the index in RITEM of the beginning of the portion
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| + for rule R.
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| +
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| + RULES[R].prec -- the symbol providing the precedence level of R.
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| +
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| + RULES[R].precsym -- the symbol attached (via %prec) to give its
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| + precedence to R. Of course, if set, it is equal to `prec', but we
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| + need to distinguish one from the other when reducing: a symbol used
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| + in a %prec is not useless.
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| +
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| + RULES[R].assoc -- the associativity of R.
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| +
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| + RULES[R].dprec -- the dynamic precedence level of R (for GLR
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| + parsing).
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| +
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| + RULES[R].merger -- index of merging function for R (for GLR
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| + parsing).
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| +
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| + RULES[R].line -- the line where R was defined.
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| +
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| + RULES[R].useful -- true iff the rule is used (i.e., false if thrown
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| + away by reduce).
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| +
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| + The right hand side is stored as symbol numbers in a portion of
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| + RITEM.
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| +
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| + The length of the portion is one greater than the number of symbols
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| + in the rule's right hand side. The last element in the portion
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| + contains minus R, which identifies it as the end of a portion and
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| + says which rule it is for.
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| +
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| + The portions of RITEM come in order of increasing rule number.
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| + NRITEMS is the total length of RITEM. Each element of RITEM is
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| + called an "item" and its index in RITEM is an item number.
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| +
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| + Item numbers are used in the finite state machine to represent
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| + places that parsing can get to.
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| +
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| + SYMBOLS[I]->prec records the precedence level of each symbol.
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| +
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| + Precedence levels are assigned in increasing order starting with 1
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| + so that numerically higher precedence values mean tighter binding
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| + as they ought to. Zero as a symbol or rule's precedence means none
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| + is assigned.
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| +
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| + Associativities are recorded similarly in SYMBOLS[I]->assoc. */
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| +
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| +# include "location.h"
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| +# include "symtab.h"
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| +
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| +# define ISTOKEN(i) ((i) < ntokens)
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| +# define ISVAR(i) ((i) >= ntokens)
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| +
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| +extern int nsyms;
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| +extern int ntokens;
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| +extern int nvars;
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| +
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| +typedef int item_number;
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| +#define ITEM_NUMBER_MAX INT_MAX
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| +extern item_number *ritem;
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| +extern unsigned int nritems;
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| +
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| +/* There is weird relationship between OT1H item_number and OTOH
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| + symbol_number and rule_number: we store the latter in
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| + item_number. symbol_number values are stored as-is, while
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| + the negation of (rule_number + 1) is stored.
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| +
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| + Therefore, a symbol_number must be a valid item_number, and we
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| + sometimes have to perform the converse transformation. */
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| +
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| +static inline item_number
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| +symbol_number_as_item_number (symbol_number sym)
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| +{
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| + return sym;
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| +}
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| +
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| +static inline symbol_number
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| +item_number_as_symbol_number (item_number i)
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| +{
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| + return i;
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| +}
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| +
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| +static inline bool
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| +item_number_is_symbol_number (item_number i)
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| +{
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| + return i >= 0;
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| +}
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| +
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| +/* Rule numbers. */
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| +typedef int rule_number;
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| +#define RULE_NUMBER_MAX INT_MAX
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| +extern rule_number nrules;
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| +
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| +static inline item_number
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| +rule_number_as_item_number (rule_number r)
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| +{
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| + return -1 - r;
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| +}
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| +
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| +static inline rule_number
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| +item_number_as_rule_number (item_number i)
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| +{
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| + return -1 - i;
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| +}
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| +
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| +static inline bool
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| +item_number_is_rule_number (item_number i)
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| +{
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| + return i < 0;
|
| +}
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| +
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| +/*--------.
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| +| Rules. |
|
| +`--------*/
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| +
|
| +typedef struct
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| +{
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| + /* The number of the rule in the source. It is usually the index in
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| + RULES too, except if there are useless rules. */
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| + rule_number user_number;
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| +
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| + /* The index in RULES. Usually the rule number in the source,
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| + except if some rules are useless. */
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| + rule_number number;
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| +
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| + symbol *lhs;
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| + item_number *rhs;
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| +
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| + /* This symbol provides both the associativity, and the precedence. */
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| + symbol *prec;
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| +
|
| + int dprec;
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| + int merger;
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| +
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| + /* This symbol was attached to the rule via %prec. */
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| + symbol *precsym;
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| +
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| + location location;
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| + bool useful;
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| +
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| + const char *action;
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| + location action_location;
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| +} rule;
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| +
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| +extern rule *rules;
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| +
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| +/* A function that selects a rule. */
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| +typedef bool (*rule_filter) (rule *);
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| +
|
| +/* Return true IFF the rule has a `number' smaller than NRULES. That is, it is
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| + useful in the grammar. */
|
| +bool rule_useful_in_grammar_p (rule *r);
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| +
|
| +/* Return true IFF the rule has a `number' higher than NRULES. That is, it is
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| + useless in the grammar. */
|
| +bool rule_useless_in_grammar_p (rule *r);
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| +
|
| +/* Return true IFF the rule is not flagged as useful but is useful in the
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| + grammar. In other words, it was discarded because of conflicts. */
|
| +bool rule_useless_in_parser_p (rule *r);
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| +
|
| +/* Print this rule's number and lhs on OUT. If a PREVIOUS_LHS was
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| + already displayed (by a previous call for another rule), avoid
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| + useless repetitions. */
|
| +void rule_lhs_print (rule *r, symbol *previous_lhs, FILE *out);
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| +void rule_lhs_print_xml (rule *r, FILE *out, int level);
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| +
|
| +/* Return the length of the RHS. */
|
| +int rule_rhs_length (rule *r);
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| +
|
| +/* Print this rule's RHS on OUT. */
|
| +void rule_rhs_print (rule *r, FILE *out);
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| +
|
| +/* Print this rule on OUT. */
|
| +void rule_print (rule *r, FILE *out);
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| +
|
| +
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| +
|
| +
|
| +/* Table of the symbols, indexed by the symbol number. */
|
| +extern symbol **symbols;
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| +
|
| +/* TOKEN_TRANSLATION -- a table indexed by a token number as returned
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| + by the user's yylex routine, it yields the internal token number
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| + used by the parser and throughout bison. */
|
| +extern symbol_number *token_translations;
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| +extern int max_user_token_number;
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| +
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| +
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| +
|
| +/* Dump RITEM for traces. */
|
| +void ritem_print (FILE *out);
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| +
|
| +/* Return the size of the longest rule RHS. */
|
| +size_t ritem_longest_rhs (void);
|
| +
|
| +/* Print the grammar's rules that match FILTER on OUT under TITLE. */
|
| +void grammar_rules_partial_print (FILE *out, const char *title,
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| + rule_filter filter);
|
| +
|
| +/* Print the grammar's useful rules on OUT. */
|
| +void grammar_rules_print (FILE *out);
|
| +/* Print all of the grammar's rules with a "usefulness" attribute. */
|
| +void grammar_rules_print_xml (FILE *out, int level);
|
| +
|
| +/* Dump the grammar. */
|
| +void grammar_dump (FILE *out, const char *title);
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| +
|
| +/* Report on STDERR the rules that are not flagged USEFUL, using the
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| + MESSAGE (which can be `rule useless in grammar' when invoked after grammar
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| + reduction, or `rule useless in parser due to conflicts' after conflicts
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| + were taken into account). */
|
| +void grammar_rules_useless_report (const char *message);
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| +
|
| +/* Free the packed grammar. */
|
| +void grammar_free (void);
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| +
|
| +#endif /* !GRAM_H_ */
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|
|
| Property changes on: bison\src\bison\2.4.1\bison-2.4.1-src\src\gram.h
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| ___________________________________________________________________
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| Added: svn:eol-style
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| + LF
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