/* Symbol table manager for Bison.
Copyright (C) 1984, 1989, 2000-2002, 2004-2012 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/>. */
#include <config.h>
#include "system.h"
#include <hash.h>
#include "complain.h"
#include "gram.h"
#include "symtab.h"
/*-------------------------------------------------------------------.
| Symbols sorted by tag. Allocated by the first invocation of |
| symbols_do, after which no more symbols should be created. |
`-------------------------------------------------------------------*/
static symbol **symbols_sorted = NULL;
/*------------------------.
| Distinguished symbols. |
`------------------------*/
symbol *errtoken = NULL;
symbol *undeftoken = NULL;
symbol *endtoken = NULL;
symbol *accept = NULL;
symbol *startsymbol = NULL;
location startsymbol_location;
/*---------------------------------------.
| Default %destructor's and %printer's. |
`---------------------------------------*/
static code_props default_tagged_destructor = CODE_PROPS_NONE_INIT;
static code_props default_tagless_destructor = CODE_PROPS_NONE_INIT;
static code_props default_tagged_printer = CODE_PROPS_NONE_INIT;
static code_props default_tagless_printer = CODE_PROPS_NONE_INIT;
/*---------------------------------.
| Create a new symbol, named TAG. |
`---------------------------------*/
static symbol *
symbol_new (uniqstr tag, location loc)
{
symbol *res = xmalloc (sizeof *res);
uniqstr_assert (tag);
/* If the tag is not a string (starts with a double quote), check
that it is valid for Yacc. */
if (tag[0] != '\"' && tag[0] != '\'' && mbschr (tag, '-'))
yacc_at (loc, _("POSIX Yacc forbids dashes in symbol names: %s"),
tag);
res->tag = tag;
res->location = loc;
res->type_name = NULL;
code_props_none_init (&res->destructor);
code_props_none_init (&res->printer);
res->number = NUMBER_UNDEFINED;
res->prec = 0;
res->assoc = undef_assoc;
res->user_token_number = USER_NUMBER_UNDEFINED;
res->alias = NULL;
res->class = unknown_sym;
res->declared = false;
if (nsyms == SYMBOL_NUMBER_MAXIMUM)
fatal (_("too many symbols in input grammar (limit is %d)"),
SYMBOL_NUMBER_MAXIMUM);
nsyms++;
return res;
}
/*----------------------------------------.
| Create a new semantic type, named TAG. |
`----------------------------------------*/
static semantic_type *
semantic_type_new (uniqstr tag)
{
semantic_type *res = xmalloc (sizeof *res);
uniqstr_assert (tag);
res->tag = tag;
code_props_none_init (&res->destructor);
code_props_none_init (&res->printer);
return res;
}
/*-----------------.
| Print a symbol. |
`-----------------*/
#define SYMBOL_ATTR_PRINT(Attr) \
if (s->Attr) \
fprintf (f, " %s { %s }", #Attr, s->Attr)
#define SYMBOL_CODE_PRINT(Attr) \
if (s->Attr.code) \
fprintf (f, " %s { %s }", #Attr, s->Attr.code)
void
symbol_print (symbol *s, FILE *f)
{
if (s)
{
fprintf (f, "\"%s\"", s->tag);
SYMBOL_ATTR_PRINT (type_name);
SYMBOL_CODE_PRINT (destructor);
SYMBOL_CODE_PRINT (printer);
}
else
fprintf (f, "<NULL>");
}
#undef SYMBOL_ATTR_PRINT
#undef SYMBOL_CODE_PRINT
/*------------------------------------------------------------------.
| Complain that S's WHAT is redeclared at SECOND, and was first set |
| at FIRST. |
`------------------------------------------------------------------*/
static void
symbol_redeclaration (symbol *s, const char *what, location first,
location second)
{
unsigned i = 0;
complain_at_indent (second, &i, _("%s redeclaration for %s"), what, s->tag);
i += SUB_INDENT;
complain_at_indent (first, &i, _("previous declaration"));
}
static void
semantic_type_redeclaration (semantic_type *s, const char *what, location first,
location second)
{
unsigned i = 0;
complain_at_indent (second, &i, _("%s redeclaration for <%s>"), what, s->tag);
i += SUB_INDENT;
complain_at_indent (first, &i, _("previous declaration"));
}
/*-----------------------------------------------------------------.
| Set the TYPE_NAME associated with SYM. Does nothing if passed 0 |
| as TYPE_NAME. |
`-----------------------------------------------------------------*/
void
symbol_type_set (symbol *sym, uniqstr type_name, location loc)
{
if (type_name)
{
if (sym->type_name)
symbol_redeclaration (sym, "%type", sym->type_location, loc);
uniqstr_assert (type_name);
sym->type_name = type_name;
sym->type_location = loc;
}
}
/*-----------------------------------------.
| Set the DESTRUCTOR associated with SYM. |
`-----------------------------------------*/
void
symbol_destructor_set (symbol *sym, code_props const *destructor)
{
if (sym->destructor.code)
symbol_redeclaration (sym, "%destructor", sym->destructor.location,
destructor->location);
sym->destructor = *destructor;
}
/*------------------------------------------.
| Set the DESTRUCTOR associated with TYPE. |
`------------------------------------------*/
void
semantic_type_destructor_set (semantic_type *type,
code_props const *destructor)
{
if (type->destructor.code)
semantic_type_redeclaration (type, "%destructor",
type->destructor.location,
destructor->location);
type->destructor = *destructor;
}
/*---------------------------------------.
| Get the computed %destructor for SYM. |
`---------------------------------------*/
code_props const *
symbol_destructor_get (symbol const *sym)
{
/* Per-symbol %destructor. */
if (sym->destructor.code)
return &sym->destructor;
/* Per-type %destructor. */
if (sym->type_name)
{
code_props const *destructor =
&semantic_type_get (sym->type_name)->destructor;
if (destructor->code)
return destructor;
}
/* Apply default %destructor's only to user-defined symbols. */
if (sym->tag[0] == '$' || sym == errtoken)
return &code_props_none;
if (sym->type_name)
return &default_tagged_destructor;
return &default_tagless_destructor;
}
/*--------------------------------------.
| Set the PRINTER associated with SYM. |
`--------------------------------------*/
void
symbol_printer_set (symbol *sym, code_props const *printer)
{
if (sym->printer.code)
symbol_redeclaration (sym, "%printer",
sym->printer.location, printer->location);
sym->printer = *printer;
}
/*---------------------------------------.
| Set the PRINTER associated with TYPE. |
`---------------------------------------*/
void
semantic_type_printer_set (semantic_type *type, code_props const *printer)
{
if (type->printer.code)
semantic_type_redeclaration (type, "%printer",
type->printer.location, printer->location);
type->printer = *printer;
}
/*------------------------------------.
| Get the computed %printer for SYM. |
`------------------------------------*/
code_props const *
symbol_printer_get (symbol const *sym)
{
/* Per-symbol %printer. */
if (sym->printer.code)
return &sym->printer;
/* Per-type %printer. */
if (sym->type_name)
{
code_props const *printer = &semantic_type_get (sym->type_name)->printer;
if (printer->code)
return printer;
}
/* Apply the default %printer only to user-defined symbols. */
if (sym->tag[0] == '$' || sym == errtoken)
return &code_props_none;
if (sym->type_name)
return &default_tagged_printer;
return &default_tagless_printer;
}
/*-----------------------------------------------------------------.
| Set the PRECEDENCE associated with SYM. Does nothing if invoked |
| with UNDEF_ASSOC as ASSOC. |
`-----------------------------------------------------------------*/
void
symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
{
if (a != undef_assoc)
{
if (sym->prec != 0)
symbol_redeclaration (sym, assoc_to_string (a), sym->prec_location,
loc);
sym->prec = prec;
sym->assoc = a;
sym->prec_location = loc;
}
/* Only terminals have a precedence. */
symbol_class_set (sym, token_sym, loc, false);
}
/*------------------------------------.
| Set the CLASS associated with SYM. |
`------------------------------------*/
void
symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
{
if (sym->class != unknown_sym && sym->class != class)
{
complain_at (loc, _("symbol %s redefined"), sym->tag);
sym->declared = false;
}
if (class == nterm_sym && sym->class != nterm_sym)
sym->number = nvars++;
else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
sym->number = ntokens++;
sym->class = class;
if (declaring)
{
if (sym->declared)
warn_at (loc, _("symbol %s redeclared"), sym->tag);
sym->declared = true;
}
}
/*------------------------------------------------.
| Set the USER_TOKEN_NUMBER associated with SYM. |
`------------------------------------------------*/
void
symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
{
int *user_token_numberp;
if (sym->user_token_number != USER_NUMBER_HAS_STRING_ALIAS)
user_token_numberp = &sym->user_token_number;
else
user_token_numberp = &sym->alias->user_token_number;
if (*user_token_numberp != USER_NUMBER_UNDEFINED
&& *user_token_numberp != user_token_number)
complain_at (loc, _("redefining user token number of %s"), sym->tag);
*user_token_numberp = user_token_number;
/* User defined $end token? */
if (user_token_number == 0)
{
endtoken = sym;
/* It is always mapped to 0, so it was already counted in
NTOKENS. */
if (endtoken->number != NUMBER_UNDEFINED)
--ntokens;
endtoken->number = 0;
}
}
/*----------------------------------------------------------.
| If SYM is not defined, report an error, and consider it a |
| nonterminal. |
`----------------------------------------------------------*/
static inline bool
symbol_check_defined (symbol *sym)
{
if (sym->class == unknown_sym)
{
complain_at
(sym->location,
_("symbol %s is used, but is not defined as a token and has no rules"),
sym->tag);
sym->class = nterm_sym;
sym->number = nvars++;
}
return true;
}
static bool
symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
{
return symbol_check_defined (sym);
}
void
symbol_make_alias (symbol *sym, symbol *str, location loc)
{
if (str->alias)
warn_at (loc, _("symbol %s used more than once as a literal string"),
str->tag);
else if (sym->alias)
warn_at (loc, _("symbol %s given more than one literal string"),
sym->tag);
else
{
str->class = token_sym;
str->user_token_number = sym->user_token_number;
sym->user_token_number = USER_NUMBER_HAS_STRING_ALIAS;
str->alias = sym;
sym->alias = str;
str->number = sym->number;
symbol_type_set (str, sym->type_name, loc);
}
}
/*---------------------------------------------------------.
| Check that THIS, and its alias, have same precedence and |
| associativity. |
`---------------------------------------------------------*/
static inline void
symbol_check_alias_consistency (symbol *this)
{
symbol *sym = this;
symbol *str = this->alias;
/* Check only the symbol in the symbol-string pair. */
if (!(this->alias
&& this->user_token_number == USER_NUMBER_HAS_STRING_ALIAS))
return;
if (str->type_name != sym->type_name)
{
if (str->type_name)
symbol_type_set (sym, str->type_name, str->type_location);
else
symbol_type_set (str, sym->type_name, sym->type_location);
}
if (str->destructor.code || sym->destructor.code)
{
if (str->destructor.code)
symbol_destructor_set (sym, &str->destructor);
else
symbol_destructor_set (str, &sym->destructor);
}
if (str->printer.code || sym->printer.code)
{
if (str->printer.code)
symbol_printer_set (sym, &str->printer);
else
symbol_printer_set (str, &sym->printer);
}
if (sym->prec || str->prec)
{
if (str->prec)
symbol_precedence_set (sym, str->prec, str->assoc,
str->prec_location);
else
symbol_precedence_set (str, sym->prec, sym->assoc,
sym->prec_location);
}
}
static bool
symbol_check_alias_consistency_processor (void *this,
void *null ATTRIBUTE_UNUSED)
{
symbol_check_alias_consistency (this);
return true;
}
/*-------------------------------------------------------------------.
| Assign a symbol number, and write the definition of the token name |
| into FDEFINES. Put in SYMBOLS. |
`-------------------------------------------------------------------*/
static inline bool
symbol_pack (symbol *this)
{
aver (this->number != NUMBER_UNDEFINED);
if (this->class == nterm_sym)
this->number += ntokens;
else if (this->user_token_number == USER_NUMBER_HAS_STRING_ALIAS)
return true;
symbols[this->number] = this;
return true;
}
static bool
symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
{
return symbol_pack (this);
}
static void
user_token_number_redeclaration (int num, symbol *first, symbol *second)
{
unsigned i = 0;
/* User token numbers are not assigned during the parsing, but in a
second step, via a traversal of the symbol table sorted on tag.
However, error messages make more sense if we keep the first
declaration first. */
if (location_cmp (first->location, second->location) > 0)
{
symbol* tmp = first;
first = second;
second = tmp;
}
complain_at_indent (second->location, &i,
_("user token number %d redeclaration for %s"),
num, second->tag);
i += SUB_INDENT;
complain_at_indent (first->location, &i,
_("previous declaration for %s"),
first->tag);
}
/*--------------------------------------------------.
| Put THIS in TOKEN_TRANSLATIONS if it is a token. |
`--------------------------------------------------*/
static inline bool
symbol_translation (symbol *this)
{
/* Non-terminal? */
if (this->class == token_sym
&& this->user_token_number != USER_NUMBER_HAS_STRING_ALIAS)
{
/* A token which translation has already been set? */
if (token_translations[this->user_token_number] != undeftoken->number)
user_token_number_redeclaration
(this->user_token_number,
symbols[token_translations[this->user_token_number]],
this);
token_translations[this->user_token_number] = this->number;
}
return true;
}
static bool
symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
{
return symbol_translation (this);
}
/*---------------------------------------.
| Symbol and semantic type hash tables. |
`---------------------------------------*/
/* Initial capacity of symbol and semantic type hash table. */
#define HT_INITIAL_CAPACITY 257
static struct hash_table *symbol_table = NULL;
static struct hash_table *semantic_type_table = NULL;
static inline bool
hash_compare_symbol (const symbol *m1, const symbol *m2)
{
/* Since tags are unique, we can compare the pointers themselves. */
return UNIQSTR_EQ (m1->tag, m2->tag);
}
static inline bool
hash_compare_semantic_type (const semantic_type *m1, const semantic_type *m2)
{
/* Since names are unique, we can compare the pointers themselves. */
return UNIQSTR_EQ (m1->tag, m2->tag);
}
static bool
hash_symbol_comparator (void const *m1, void const *m2)
{
return hash_compare_symbol (m1, m2);
}
static bool
hash_semantic_type_comparator (void const *m1, void const *m2)
{
return hash_compare_semantic_type (m1, m2);
}
static inline size_t
hash_symbol (const symbol *m, size_t tablesize)
{
/* Since tags are unique, we can hash the pointer itself. */
return ((uintptr_t) m->tag) % tablesize;
}
static inline size_t
hash_semantic_type (const semantic_type *m, size_t tablesize)
{
/* Since names are unique, we can hash the pointer itself. */
return ((uintptr_t) m->tag) % tablesize;
}
static size_t
hash_symbol_hasher (void const *m, size_t tablesize)
{
return hash_symbol (m, tablesize);
}
static size_t
hash_semantic_type_hasher (void const *m, size_t tablesize)
{
return hash_semantic_type (m, tablesize);
}
/*-------------------------------.
| Create the symbol hash table. |
`-------------------------------*/
void
symbols_new (void)
{
symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
NULL,
hash_symbol_hasher,
hash_symbol_comparator,
free);
semantic_type_table = hash_initialize (HT_INITIAL_CAPACITY,
NULL,
hash_semantic_type_hasher,
hash_semantic_type_comparator,
free);
}
/*----------------------------------------------------------------.
| Find the symbol named KEY, and return it. If it does not exist |
| yet, create it. |
`----------------------------------------------------------------*/
symbol *
symbol_from_uniqstr (const uniqstr key, location loc)
{
symbol probe;
symbol *entry;
probe.tag = key;
entry = hash_lookup (symbol_table, &probe);
if (!entry)
{
/* First insertion in the hash. */
aver (!symbols_sorted);
entry = symbol_new (key, loc);
if (!hash_insert (symbol_table, entry))
xalloc_die ();
}
return entry;
}
/*-----------------------------------------------------------------------.
| Find the semantic type named KEY, and return it. If it does not exist |
| yet, create it. |
`-----------------------------------------------------------------------*/
semantic_type *
semantic_type_from_uniqstr (const uniqstr key)
{
semantic_type probe;
semantic_type *entry;
probe.tag = key;
entry = hash_lookup (semantic_type_table, &probe);
if (!entry)
{
/* First insertion in the hash. */
entry = semantic_type_new (key);
if (!hash_insert (semantic_type_table, entry))
xalloc_die ();
}
return entry;
}
/*----------------------------------------------------------------.
| Find the symbol named KEY, and return it. If it does not exist |
| yet, create it. |
`----------------------------------------------------------------*/
symbol *
symbol_get (const char *key, location loc)
{
return symbol_from_uniqstr (uniqstr_new (key), loc);
}
/*-----------------------------------------------------------------------.
| Find the semantic type named KEY, and return it. If it does not exist |
| yet, create it. |
`-----------------------------------------------------------------------*/
semantic_type *
semantic_type_get (const char *key)
{
return semantic_type_from_uniqstr (uniqstr_new (key));
}
/*------------------------------------------------------------------.
| Generate a dummy nonterminal, whose name cannot conflict with the |
| user's names. |
`------------------------------------------------------------------*/
symbol *
dummy_symbol_get (location loc)
{
/* Incremented for each generated symbol. */
static int dummy_count = 0;
static char buf[256];
symbol *sym;
sprintf (buf, "$@%d", ++dummy_count);
sym = symbol_get (buf, loc);
sym->class = nterm_sym;
sym->number = nvars++;
return sym;
}
bool
symbol_is_dummy (const symbol *sym)
{
return sym->tag[0] == '@' || (sym->tag[0] == '$' && sym->tag[1] == '@');
}
/*-------------------.
| Free the symbols. |
`-------------------*/
void
symbols_free (void)
{
hash_free (symbol_table);
hash_free (semantic_type_table);
free (symbols);
free (symbols_sorted);
}
/*---------------------------------------------------------------.
| Look for undefined symbols, report an error, and consider them |
| terminals. |
`---------------------------------------------------------------*/
static int
symbols_cmp (symbol const *a, symbol const *b)
{
return strcmp (a->tag, b->tag);
}
static int
symbols_cmp_qsort (void const *a, void const *b)
{
return symbols_cmp (*(symbol * const *)a, *(symbol * const *)b);
}
static void
symbols_do (Hash_processor processor, void *processor_data)
{
size_t count = hash_get_n_entries (symbol_table);
if (!symbols_sorted)
{
symbols_sorted = xnmalloc (count, sizeof *symbols_sorted);
hash_get_entries (symbol_table, (void**)symbols_sorted, count);
qsort (symbols_sorted, count, sizeof *symbols_sorted,
symbols_cmp_qsort);
}
{
size_t i;
for (i = 0; i < count; ++i)
processor (symbols_sorted[i], processor_data);
}
}
/*--------------------------------------------------------------.
| Check that all the symbols are defined. Report any undefined |
| symbols and consider them nonterminals. |
`--------------------------------------------------------------*/
void
symbols_check_defined (void)
{
symbols_do (symbol_check_defined_processor, NULL);
}
/*------------------------------------------------------------------.
| Set TOKEN_TRANSLATIONS. Check that no two symbols share the same |
| number. |
`------------------------------------------------------------------*/
static void
symbols_token_translations_init (void)
{
bool num_256_available_p = true;
int i;
/* Find the highest user token number, and whether 256, the POSIX
preferred user token number for the error token, is used. */
max_user_token_number = 0;
for (i = 0; i < ntokens; ++i)
{
symbol *this = symbols[i];
if (this->user_token_number != USER_NUMBER_UNDEFINED)
{
if (this->user_token_number > max_user_token_number)
max_user_token_number = this->user_token_number;
if (this->user_token_number == 256)
num_256_available_p = false;
}
}
/* If 256 is not used, assign it to error, to follow POSIX. */
if (num_256_available_p
&& errtoken->user_token_number == USER_NUMBER_UNDEFINED)
errtoken->user_token_number = 256;
/* Set the missing user numbers. */
if (max_user_token_number < 256)
max_user_token_number = 256;
for (i = 0; i < ntokens; ++i)
{
symbol *this = symbols[i];
if (this->user_token_number == USER_NUMBER_UNDEFINED)
this->user_token_number = ++max_user_token_number;
if (this->user_token_number > max_user_token_number)
max_user_token_number = this->user_token_number;
}
token_translations = xnmalloc (max_user_token_number + 1,
sizeof *token_translations);
/* Initialize all entries for literal tokens to 2, the internal
token number for $undefined, which represents all invalid inputs.
*/
for (i = 0; i < max_user_token_number + 1; i++)
token_translations[i] = undeftoken->number;
symbols_do (symbol_translation_processor, NULL);
}
/*----------------------------------------------------------------.
| Assign symbol numbers, and write definition of token names into |
| FDEFINES. Set up vectors SYMBOL_TABLE, TAGS of symbols. |
`----------------------------------------------------------------*/
void
symbols_pack (void)
{
symbols_do (symbol_check_alias_consistency_processor, NULL);
symbols = xcalloc (nsyms, sizeof *symbols);
symbols_do (symbol_pack_processor, NULL);
/* Aliases leave empty slots in symbols, so remove them. */
{
int writei;
int readi;
int nsyms_old = nsyms;
for (writei = 0, readi = 0; readi < nsyms_old; readi += 1)
{
if (symbols[readi] == NULL)
{
nsyms -= 1;
ntokens -= 1;
}
else
{
symbols[writei] = symbols[readi];
symbols[writei]->number = writei;
if (symbols[writei]->alias)
symbols[writei]->alias->number = writei;
writei += 1;
}
}
}
symbols = xnrealloc (symbols, nsyms, sizeof *symbols);
symbols_token_translations_init ();
if (startsymbol->class == unknown_sym)
fatal_at (startsymbol_location,
_("the start symbol %s is undefined"),
startsymbol->tag);
else if (startsymbol->class == token_sym)
fatal_at (startsymbol_location,
_("the start symbol %s is a token"),
startsymbol->tag);
}
/*--------------------------------------------------.
| Set default tagged/tagless %destructor/%printer. |
`--------------------------------------------------*/
void
default_tagged_destructor_set (code_props const *destructor)
{
if (default_tagged_destructor.code)
{
unsigned i = 0;
complain_at_indent (destructor->location, &i,
_("redeclaration for default tagged %%destructor"));
i += SUB_INDENT;
complain_at_indent (default_tagged_destructor.location, &i,
_("previous declaration"));
}
default_tagged_destructor = *destructor;
}
void
default_tagless_destructor_set (code_props const *destructor)
{
if (default_tagless_destructor.code)
{
unsigned i = 0;
complain_at_indent (destructor->location, &i,
_("redeclaration for default tagless %%destructor"));
i += SUB_INDENT;
complain_at_indent (default_tagless_destructor.location, &i,
_("previous declaration"));
}
default_tagless_destructor = *destructor;
}
void
default_tagged_printer_set (code_props const *printer)
{
if (default_tagged_printer.code)
{
unsigned i = 0;
complain_at_indent (printer->location, &i,
_("redeclaration for default tagged %%printer"));
i += SUB_INDENT;
complain_at_indent (default_tagged_printer.location, &i,
_("previous declaration"));
}
default_tagged_printer = *printer;
}
void
default_tagless_printer_set (code_props const *printer)
{
if (default_tagless_printer.code)
{
unsigned i = 0;
complain_at_indent (printer->location, &i,
_("redeclaration for default tagless %%printer"));
i += SUB_INDENT;
complain_at_indent (default_tagless_printer.location, &i,
_("previous declaration"));
}
default_tagless_printer = *printer;
}