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0e78e603f6
and rule_table. * src/reader.c (packsymbols): Fill this table. Drop sprec. * src/conflicts.c (resolve_sr_conflict): Adjust. * src/reduce.c (reduce_grammar): Adjust: just sort symbols, a single table. Use symbols[i]->tag instead of tags[i].
169 lines
4.9 KiB
C
169 lines
4.9 KiB
C
/* Data definitions for internal representation of bison's input,
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Copyright 1984, 1986, 1989, 1992, 2001 Free Software Foundation, Inc.
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This file is part of Bison, the GNU Compiler Compiler.
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Bison 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 2, or (at your option)
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any later version.
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Bison is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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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
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along with Bison; see the file COPYING. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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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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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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(the true number of token values assigned is ntokens reduced by one
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for each alias declaration)
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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 are
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for variables. Symbol number zero is the end-of-input token. This
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token is counted in ntokens.
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The rules receive rule numbers 1 to nrules in the order they are
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written. Actions and guards are accessed via the rule number.
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The rules themselves are described by several arrays: amongst which
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RITEM, and RULE_TABLE.
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RULE_TABLE is an array of struct rule_s, which members are:
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RULE_TABLE[R].lhs -- the symbol number of the left hand side of
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rule R. If -1, the rule has been thrown out by reduce.c and should
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be ignored.
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RULE_TABLE[R].rhs -- the index in RITEM of the beginning of the
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portion for rule R.
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RULE_TABLE[R].prec -- the precedence level of R.
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RULE_TABLE[R].precsym -- the symbol-number of the symbol in %prec
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for R (if any).
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RULE_TABLE[R].assoc -- the associativity of R.
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RULE_TABLE[R].line -- the line where R was defined.
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RULE_TABLE[R].useful -- TRUE iff the rule is used.
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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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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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The portions of RITEM come in order of increasing rule number and
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are followed by an element which is zero to mark the end. nitems
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is the total length of ritem, not counting the final zero. Each
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element of ritem is called an "item" and its index in ritem is an
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item number.
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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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SPREC records the precedence level of each symbol.
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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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Associativities are recorded similarly in rassoc and sassoc. */
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#define ISTOKEN(s) ((s) < ntokens)
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#define ISVAR(s) ((s) >= ntokens)
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extern int nitems;
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extern int nrules;
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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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extern short *ritem;
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extern int nritems;
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extern short *sprec;
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extern short *sassoc;
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extern int start_symbol;
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/* associativity values in elements of rassoc, sassoc. */
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typedef enum
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{
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right_assoc,
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left_assoc,
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non_assoc
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} associativity;
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typedef struct rule_s
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{
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short lhs;
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short rhs;
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short prec;
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short precsym;
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short assoc;
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short line;
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bool useful;
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const char *action;
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short action_line;
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const char *guard;
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short guard_line;
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} rule_t;
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extern struct rule_s *rule_table;
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/* Table of the symbols, indexed by the symbol number. */
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extern struct bucket **symbols;
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/* token translation table: indexed by a token number as returned by
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the user's yylex routine, it yields the internal token number used
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by the parser and throughout bison. */
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extern short *token_translations;
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extern int max_user_token_number;
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/* SEMANTIC_PARSER is nonzero if the input file says to use the hairy
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parser that provides for semantic error recovery. If it is zero,
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the yacc-compatible simplified parser is used. */
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extern int semantic_parser;
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/* PURE_PARSER is nonzero if should generate a parser that is all pure
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and reentrant. */
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extern int pure_parser;
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/* ERROR_TOKEN_NUMBER is the token number of the error token. */
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extern int error_token_number;
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/* Dump RITEM for traces. */
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void ritem_print PARAMS ((FILE *out));
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/* Return the size of the longest rule RHS. */
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size_t ritem_longest_rhs PARAMS ((void));
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#endif /* !GRAM_H_ */
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