/* Definitions for symtab.c and callers, part of Bison.
Copyright (C) 1984, 1989, 1992, 2000-2002, 2004-2015 Free Software
Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/**
* \file symtab.h
* \brief Manipulating ::symbol.
*/
#ifndef SYMTAB_H_
# define SYMTAB_H_
# include "assoc.h"
# include "location.h"
# include "scan-code.h"
# include "uniqstr.h"
/*----------.
| Symbols. |
`----------*/
/** Symbol classes. */
typedef enum
{
unknown_sym, /**< Undefined. */
token_sym, /**< Terminal. */
nterm_sym /**< Non-terminal. */
} symbol_class;
/** Internal token numbers. */
typedef int symbol_number;
# define SYMBOL_NUMBER_MAXIMUM INT_MAX
typedef struct symbol symbol;
/* Declaration status of a symbol.
First, it is "undeclared". Then, if "undeclared" and used in a
%printer/%destructor, it is "used". If not "declared" but used in
a rule, it is "needed". Finally, if declared (via a rule for
nonterminals, or %token), it is "declared".
When status are checked at the end, "declared" symbols are fine,
"used" symbols trigger warnings, otherwise it's an error. */
typedef enum
{
/** Used in the input file for an unknown reason (error). */
undeclared,
/** Used by %destructor/%printer but not defined (warning). */
used,
/** Used in the gramar (rules) but not defined (error). */
needed,
/** Defined with %type or %token (good). */
declared,
} status;
enum code_props_type
{
destructor = 0,
printer = 1,
};
typedef enum code_props_type code_props_type;
enum { CODE_PROPS_SIZE = 2 };
/* When extending this structure, be sure to complete
symbol_check_alias_consistency. */
struct symbol
{
/** The key, name of the symbol. */
uniqstr tag;
/** The location of its first occurrence. */
location location;
/** Its \c \%type.
Beware that this is the type_name as was entered by the user,
including silly things such as "]" if she entered "%token <]> t".
Therefore, when outputting type_name to M4, be sure to escape it
into "@}". See quoted_output for instance. */
uniqstr type_name;
/** Its \c \%type's location. */
location type_location;
/** Any \c \%destructor (resp. \%printer) declared specificially for this
symbol.
Access this field only through <tt>symbol</tt>'s interface functions. For
example, if <tt>symbol::destructor = NULL</tt> (resp. <tt>symbol::printer
= NULL</tt>), a default \c \%destructor (resp. \%printer) or a per-type
\c symbol_destructor_printer_get will compute the correct one. */
code_props props[CODE_PROPS_SIZE];
symbol_number number;
location prec_location;
int prec;
assoc assoc;
int user_token_number;
/* Points to the other in the symbol-string pair for an alias.
Special value USER_NUMBER_HAS_STRING_ALIAS in the symbol half of the
symbol-string pair for an alias. */
symbol *alias;
symbol_class class;
status status;
};
/** Undefined user number. */
# define USER_NUMBER_UNDEFINED -1
/* 'symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
this symbol has a literal string alias. For instance, '%token foo
"foo"' has '"foo"' numbered regularly, and 'foo' numbered as
USER_NUMBER_HAS_STRING_ALIAS. */
# define USER_NUMBER_HAS_STRING_ALIAS -9991
/* Undefined internal token number. */
# define NUMBER_UNDEFINED (-1)
/** Fetch (or create) the symbol associated to KEY. */
symbol *symbol_from_uniqstr (const uniqstr key, location loc);
/** Fetch (or create) the symbol associated to KEY. */
symbol *symbol_get (const char *key, location loc);
/** Generate a dummy nonterminal.
Its name cannot conflict with the user's names. */
symbol *dummy_symbol_get (location loc);
/*--------------------.
| Methods on symbol. |
`--------------------*/
/** Print a symbol (for debugging). */
void symbol_print (symbol const *s, FILE *f);
/** Is this a dummy nonterminal? */
bool symbol_is_dummy (const symbol *sym);
/** The name of the code_props type: "\%destructor" or "\%printer". */
char const *code_props_type_string (code_props_type kind);
/** The name of the symbol that can be used as an identifier.
** Consider the alias if needed.
** Return 0 if there is none (e.g., the symbol is only defined as
** a string). */
uniqstr symbol_id_get (symbol const *sym);
/**
* Make \c str the literal string alias of \c sym. Copy token number,
* symbol number, and type from \c sym to \c str.
*/
void symbol_make_alias (symbol *sym, symbol *str, location loc);
/** Set the \c type_name associated with \c sym.
Do nothing if passed 0 as \c type_name. */
void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
/** Set the \c \%destructor or \c \%printer associated with \c sym. */
void symbol_code_props_set (symbol *sym, code_props_type kind,
code_props const *destructor);
/** Get the computed \c \%destructor or \c %printer for \c sym, which was
initialized with \c code_props_none_init if there's no \c \%destructor or
\c %printer. */
code_props *symbol_code_props_get (symbol *sym, code_props_type kind);
/** Set the \c precedence associated with \c sym.
Ensure that \a symbol is a terminal.
Do nothing if invoked with \c undef_assoc as \c assoc. */
void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
/** Set the \c class associated with \c sym. */
void symbol_class_set (symbol *sym, symbol_class class, location loc,
bool declaring);
/** Set the \c user_token_number associated with \c sym. */
void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
/*------------------.
| Special symbols. |
`------------------*/
/** The error token. */
extern symbol *errtoken;
/** The token for unknown tokens. */
extern symbol *undeftoken;
/** The end of input token. */
extern symbol *endtoken;
/** The genuine start symbol.
$accept: start-symbol $end */
extern symbol *accept;
/** The user start symbol. */
extern symbol *startsymbol;
/** The location of the \c \%start declaration. */
extern location startsymbol_location;
/*-------------------.
| Symbol Relations. |
`-------------------*/
/* The symbol relations are represented by a directed graph. */
/* The id of a node */
typedef int graphid;
typedef struct symgraphlink symgraphlink;
struct symgraphlink
{
/** The second \c symbol or group of a precedence relation.
* See \c symgraph. */
graphid id;
symgraphlink *next;
};
/* Symbol precedence graph, to store the used precedence relations between
* symbols. */
typedef struct symgraph symgraph;
struct symgraph
{
/** Identifier for the node: equal to the number of the symbol. */
graphid id;
/** The list of related symbols that have a smaller precedence. */
symgraphlink *succ;
/** The list of related symbols that have a greater precedence. */
symgraphlink *pred;
};
/** Register a new precedence relation as used. */
void register_precedence (graphid first, graphid snd);
/** Print a warning for each symbol whose precedence and/or associativity
* is useless. */
void print_precedence_warnings (void);
/*----------------------.
| Symbol associativity |
`----------------------*/
void register_assoc (graphid i, graphid j);
/*-----------------.
| Semantic types. |
`-----------------*/
/** A semantic type and its associated \c \%destructor and \c \%printer.
Access the fields of this struct only through the interface functions in
this file. \sa symbol::destructor */
typedef struct {
/** The key, name of the semantic type. */
uniqstr tag;
/** The location of its first occurence. */
location location;
/** Its status : "undeclared", "used" or "declared".
It cannot be "needed". */
status status;
/** Any \c %destructor and %printer declared for this
semantic type. */
code_props props[CODE_PROPS_SIZE];
} semantic_type;
/** Fetch (or create) the semantic type associated to KEY. */
semantic_type *semantic_type_from_uniqstr (const uniqstr key,
const location *loc);
/** Fetch (or create) the semantic type associated to KEY. */
semantic_type *semantic_type_get (const char *key, const location *loc);
/** Set the \c destructor or \c printer associated with \c type. */
void semantic_type_code_props_set (semantic_type *type,
code_props_type kind,
code_props const *code);
/*----------------------------------.
| Symbol and semantic type tables. |
`----------------------------------*/
/** Create the symbol and semantic type tables. */
void symbols_new (void);
/** Free all the memory allocated for symbols and semantic types. */
void symbols_free (void);
/** Check that all the symbols are defined.
Report any undefined symbols and consider them nonterminals. */
void symbols_check_defined (void);
/** Sanity checks and #token_translations construction.
Perform various sanity checks, assign symbol numbers, and set up
#token_translations. */
void symbols_pack (void);
#endif /* !SYMTAB_H_ */