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366 lines
10 KiB
C
366 lines
10 KiB
C
/* Definitions for symtab.c and callers, part of Bison.
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Copyright (C) 1984, 1989, 1992, 2000-2002, 2004-2015, 2018-2021 Free
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Software Foundation, Inc.
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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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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
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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 this program. If not, see <https://www.gnu.org/licenses/>. */
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/**
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* \file symtab.h
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* \brief Manipulating ::symbol.
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*/
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#ifndef SYMTAB_H_
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# define SYMTAB_H_
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# include "assoc.h"
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# include "location.h"
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# include "scan-code.h"
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# include "uniqstr.h"
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/*----------.
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| Symbols. |
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`----------*/
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/** Symbol classes. */
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typedef enum
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{
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/** Undefined. */
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unknown_sym,
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/** Declared with %type: same as Undefined, but triggered a Wyacc if
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applied to a terminal. */
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pct_type_sym,
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/** Terminal. */
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token_sym,
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/** Nonterminal. */
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nterm_sym
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} symbol_class;
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/** Internal token numbers. */
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typedef int symbol_number;
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# define SYMBOL_NUMBER_MAXIMUM INT_MAX
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typedef struct symbol symbol;
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typedef struct sym_content sym_content;
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/* Declaration status of a symbol.
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First, it is "undeclared". Then, if "undeclared" and used in a
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%printer/%destructor, it is "used". If not "declared" but used in
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a rule, it is "needed". Finally, if declared (via a rule for
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nonterminals, or %token), it is "declared".
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When status are checked at the end, "declared" symbols are fine,
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"used" symbols trigger warnings, otherwise it's an error. */
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typedef enum
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{
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/** Used in the input file for an unknown reason (error). */
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undeclared,
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/** Used by %destructor/%printer but not defined (warning). */
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used,
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/** Used in the grammar (rules) but not defined (error). */
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needed,
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/** Defined with %type or %token (good). */
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declared,
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} declaration_status;
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enum code_props_type
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{
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destructor = 0,
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printer = 1,
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};
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typedef enum code_props_type code_props_type;
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enum { CODE_PROPS_SIZE = 2 };
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struct symbol
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{
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/** The key, name of the symbol. */
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uniqstr tag;
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/** The "defining" location. */
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location location;
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/** Whether this symbol is translatable. */
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bool translatable;
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/** Whether \a location is about the first uses as left-hand side
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symbol of a rule (true), or simply the first occurrence (e.g.,
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in a %type, or as a rhs symbol of a rule). The former type of
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location is more natural in error messages. This Boolean helps
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moving from location of the first occurrence to first use as
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lhs. */
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bool location_of_lhs;
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/** Points to the other in the symbol-string pair for an alias. */
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symbol *alias;
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/** Whether this symbol is the alias of another or not. */
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bool is_alias;
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/** All the info about the pointed symbol is there. */
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sym_content *content;
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};
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struct sym_content
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{
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/** The main symbol that denotes this content (it contains the
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possible alias). */
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symbol *symbol;
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/** Its \c \%type.
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Beware that this is the type_name as was entered by the user,
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including silly things such as "]" if she entered "%token <]> t".
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Therefore, when outputting type_name to M4, be sure to escape it
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into "@}". See quoted_output for instance. */
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uniqstr type_name;
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/** Its \c \%type's location. */
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location type_loc;
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/** Any \c \%destructor (resp. \%printer) declared specifically for this
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symbol.
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Access this field only through <tt>symbol</tt>'s interface functions. For
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example, if <tt>symbol::destructor = NULL</tt> (resp. <tt>symbol::printer
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= NULL</tt>), a default \c \%destructor (resp. \%printer) or a per-type
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\c symbol_destructor_printer_get will compute the correct one. */
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code_props props[CODE_PROPS_SIZE];
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symbol_number number;
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location prec_loc;
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int prec;
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assoc assoc;
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/** Token code, possibly specified by the user (%token FOO 42). */
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int code;
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symbol_class class;
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declaration_status status;
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};
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/** Fetch (or create) the symbol associated to KEY. */
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symbol *symbol_from_uniqstr (const uniqstr key, location loc);
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/** Fetch (or create) the symbol associated to KEY. */
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symbol *symbol_get (const char *key, location loc);
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/** Generate a dummy nonterminal.
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Its name cannot conflict with the user's names. */
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symbol *dummy_symbol_get (location loc);
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/*--------------------.
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| Methods on symbol. |
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`--------------------*/
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/** Print a symbol (for debugging). */
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void symbol_print (symbol const *s, FILE *f);
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/** Is this a dummy nonterminal? */
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bool symbol_is_dummy (symbol const *sym);
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/** The name of the code_props type: "\%destructor" or "\%printer". */
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char const *code_props_type_string (code_props_type kind);
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/** The name of the symbol that can be used as an identifier.
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** Consider the alias if needed.
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** Return 0 if there is none (e.g., the symbol is only defined as
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** a string). */
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uniqstr symbol_id_get (symbol const *sym);
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/**
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* Make \c str the literal string alias of \c sym. Copy token number,
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* symbol number, and type from \c sym to \c str.
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*/
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void symbol_make_alias (symbol *sym, symbol *str, location loc);
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/**
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* This symbol is used as the lhs of a rule. Record this location
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* as definition point, if not already done.
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*/
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void symbol_location_as_lhs_set (symbol *sym, location loc);
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/** Set the \c type_name associated with \c sym.
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Do nothing if passed 0 as \c type_name. */
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void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
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/** Set the \c \%destructor or \c \%printer associated with \c sym. */
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void symbol_code_props_set (symbol *sym, code_props_type kind,
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code_props const *destructor);
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/** Get the computed \c \%destructor or \c %printer for \c sym, which was
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initialized with \c code_props_none_init if there's no \c \%destructor or
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\c %printer. */
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code_props *symbol_code_props_get (symbol *sym, code_props_type kind);
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/** Set the \c precedence associated with \c sym.
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Ensure that \a symbol is a terminal.
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Do nothing if invoked with \c undef_assoc as \c assoc. */
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void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
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/** Set the \c class associated with \c sym.
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Whether \c declaring means whether this class definition comes
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from %nterm or %token (but not %type, prec/assoc, etc.). A symbol
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can have "declaring" set only at most once. */
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void symbol_class_set (symbol *sym, symbol_class class, location loc,
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bool declaring);
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/** Set the token \c code of \c sym, specified by the user at \c loc. */
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void symbol_code_set (symbol *sym, int code, location loc);
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/*------------------.
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| Special symbols. |
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`------------------*/
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/** The error token. */
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extern symbol *errtoken;
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/** The token for unknown tokens. */
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extern symbol *undeftoken;
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/** The end of input token. */
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extern symbol *eoftoken;
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/** The genuine start symbol.
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$accept: start-symbol $end */
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extern symbol *acceptsymbol;
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/** Whether a symbol declared with a type tag. */
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extern bool tag_seen;
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/*-------------------.
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| Symbol Relations. |
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`-------------------*/
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/* The symbol relations are represented by a directed graph. */
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/* The id of a node */
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typedef int graphid;
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typedef struct symgraphlink symgraphlink;
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struct symgraphlink
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{
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/** The second \c symbol or group of a precedence relation.
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* See \c symgraph. */
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graphid id;
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symgraphlink *next;
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};
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/* Symbol precedence graph, to store the used precedence relations between
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* symbols. */
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typedef struct symgraph symgraph;
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struct symgraph
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{
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/** Identifier for the node: equal to the number of the symbol. */
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graphid id;
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/** The list of related symbols that have a smaller precedence. */
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symgraphlink *succ;
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/** The list of related symbols that have a greater precedence. */
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symgraphlink *pred;
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};
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/** Register a new precedence relation as used. */
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void register_precedence (graphid first, graphid snd);
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/** Print a warning for each symbol whose precedence and/or associativity
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* is useless. */
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void print_precedence_warnings (void);
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/*----------------------.
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| Symbol associativity |
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`----------------------*/
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void register_assoc (graphid i, graphid j);
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/*-----------------.
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| Semantic types. |
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`-----------------*/
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/** A semantic type and its associated \c \%destructor and \c \%printer.
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Access the fields of this struct only through the interface functions in
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this file. \sa symbol::destructor */
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typedef struct {
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/** The key, name of the semantic type. */
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uniqstr tag;
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/** The location of its first occurrence. */
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location location;
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/** Its status : "undeclared", "used" or "declared".
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It cannot be "needed". */
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declaration_status status;
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/** Any \c %destructor and %printer declared for this
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semantic type. */
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code_props props[CODE_PROPS_SIZE];
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} semantic_type;
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/** Fetch (or create) the semantic type associated to KEY. */
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semantic_type *semantic_type_from_uniqstr (const uniqstr key,
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const location *loc);
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/** Fetch (or create) the semantic type associated to KEY. */
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semantic_type *semantic_type_get (const char *key, const location *loc);
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/** Set the \c destructor or \c printer associated with \c type. */
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void semantic_type_code_props_set (semantic_type *type,
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code_props_type kind,
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code_props const *code);
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/*----------------------------------.
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| Symbol and semantic type tables. |
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`----------------------------------*/
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/** Create the symbol and semantic type tables, and the built-in
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symbols. */
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void symbols_new (void);
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/** Free all the memory allocated for symbols and semantic types. */
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void symbols_free (void);
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/** Check that all the symbols are defined.
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Report any undefined symbols and consider them nonterminals. */
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void symbols_check_defined (void);
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/** Sanity checks and #token_translations construction.
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Perform various sanity checks, assign symbol numbers, and set up
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#token_translations. */
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void symbols_pack (void);
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#endif /* !SYMTAB_H_ */
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