X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/95e36146a5be4c921c14f82ab80e3612866c4518..c0cac722f7e5d7498528a67a37477cdf9ed1745c:/src/symtab.c?ds=inline diff --git a/src/symtab.c b/src/symtab.c index 08361539..7b313120 100644 --- a/src/symtab.c +++ b/src/symtab.c @@ -1,5 +1,5 @@ /* Symbol table manager for Bison, - Copyright (C) 1984, 1989, 2000 Free Software Foundation, Inc. + Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -20,108 +20,555 @@ #include "system.h" -#include "xalloc.h" +#include "quotearg.h" +#include "hash.h" +#include "complain.h" #include "symtab.h" #include "gram.h" +/*------------------------. +| Distinguished symbols. | +`------------------------*/ -bucket *firstsymbol; -static bucket *lastsymbol; -static bucket **symtab; +symbol_t *errtoken = NULL; +symbol_t *undeftoken = NULL; +symbol_t *endtoken = NULL; +symbol_t *accept = NULL; +symbol_t *startsymbol = NULL; +location_t startsymbol_location; -static int -hash (const char *key) +/*---------------------------------. +| Create a new symbol, named TAG. | +`---------------------------------*/ + +static symbol_t * +symbol_new (const char *tag, location_t location) { - const char *cp; - int k; + symbol_t *res = XMALLOC (symbol_t, 1); + + res->tag = xstrdup (tag); + res->location = location; + + res->type_name = NULL; + res->destructor = NULL; + res->printer = NULL; - cp = key; - k = 0; - while (*cp) - k = ((k << 1) ^ (*cp++)) & 0x3fff; + res->number = NUMBER_UNDEFINED; + res->prec = 0; + res->assoc = undef_assoc; + res->user_token_number = USER_NUMBER_UNDEFINED; - return k % TABSIZE; + res->alias = NULL; + res->class = unknown_sym; + + nsyms++; + return res; } +/*------------------------------------------------------------------. +| Set the TYPE_NAME associated to SYMBOL. Does nothing if passed 0 | +| as TYPE_NAME. | +`------------------------------------------------------------------*/ + void -tabinit (void) +symbol_type_set (symbol_t *symbol, char *type_name, location_t location) { - symtab = XCALLOC (bucket *, TABSIZE); + if (type_name) + { + if (symbol->type_name) + complain_at (location, + _("type redeclaration for %s"), symbol->tag); + symbol->type_name = type_name; + } +} + + +/*-------------------------------------------------------------------. +| Set the DESTRUCTOR associated to SYMBOL. Do nothing if passed 0. | +`-------------------------------------------------------------------*/ - firstsymbol = NULL; - lastsymbol = NULL; +void +symbol_destructor_set (symbol_t *symbol, char *destructor, location_t location) +{ + if (destructor) + { + if (symbol->destructor) + complain_at (location, + _("%s redeclaration for %s"), + "%destructor", symbol->tag); + symbol->destructor = destructor; + symbol->destructor_location = location; + } } -bucket * -getsym (const char *key) +/*----------------------------------------------------------------. +| Set the PRITNER associated to SYMBOL. Do nothing if passed 0. | +`----------------------------------------------------------------*/ + +void +symbol_printer_set (symbol_t *symbol, char *printer, location_t location) { - int hashval; - bucket *bp; - int found; + if (printer) + { + if (symbol->printer) + complain_at (location, + _("%s redeclaration for %s"), + "%printer", symbol->tag); + symbol->printer = printer; + symbol->printer_location = location; + } +} + - hashval = hash (key); - bp = symtab[hashval]; +/*------------------------------------------------------------------. +| Set the PRECEDENCE associated to SYMBOL. Does nothing if invoked | +| with UNDEF_ASSOC as ASSOC. | +`------------------------------------------------------------------*/ - found = 0; - while (bp != NULL && found == 0) +void +symbol_precedence_set (symbol_t *symbol, + int prec, assoc_t assoc, location_t location) +{ + if (assoc != undef_assoc) { - if (strcmp (key, bp->tag) == 0) - found = 1; - else - bp = bp->link; + if (symbol->prec != 0) + complain_at (location, + _("redefining precedence of %s"), + symbol->tag); + symbol->prec = prec; + symbol->assoc = assoc; } - if (found == 0) + /* Only terminals have a precedence. */ + symbol_class_set (symbol, token_sym, location); +} + + +/*-------------------------------------. +| Set the CLASS associated to SYMBOL. | +`-------------------------------------*/ + +void +symbol_class_set (symbol_t *symbol, symbol_class class, location_t location) +{ + if (symbol->class != unknown_sym && symbol->class != class) + complain_at (location, _("symbol %s redefined"), symbol->tag); + + if (class == nterm_sym && symbol->class != nterm_sym) + symbol->number = nvars++; + else if (class == token_sym && symbol->number == NUMBER_UNDEFINED) + symbol->number = ntokens++; + + symbol->class = class; +} + + +/*-------------------------------------------------. +| Set the USER_TOKEN_NUMBER associated to SYMBOL. | +`-------------------------------------------------*/ + +void +symbol_user_token_number_set (symbol_t *symbol, + int user_token_number, location_t location) +{ + assert (symbol->class == token_sym); + + if (symbol->user_token_number != USER_NUMBER_UNDEFINED + && symbol->user_token_number != user_token_number) + complain_at (location, _("redefining user token number of %s"), + symbol->tag); + + symbol->user_token_number = user_token_number; + /* User defined $end token? */ + if (user_token_number == 0) { - nsyms++; + endtoken = symbol; + endtoken->number = 0; + /* It is always mapped to 0, so it was already counted in + NTOKENS. */ + --ntokens; + } +} - bp = XCALLOC (bucket, 1); - bp->link = symtab[hashval]; - bp->next = NULL; - bp->tag = xstrdup (key); - bp->class = unknown_sym; - if (firstsymbol == NULL) +/*------------. +| Free THIS. | +`------------*/ + +static void +symbol_free (symbol_t *this) +{ +#if 0 + /* This causes crashes because one string can appear more + than once. */ + XFREE (this->type_name); +#endif + XFREE (this->tag); + XFREE (this); +} + + +/*-----------------------------------------------------------. +| If THIS is not defined, report an error, and consider it a | +| nonterminal. | +`-----------------------------------------------------------*/ + +static bool +symbol_check_defined (symbol_t *this) +{ + if (this->class == unknown_sym) + { + complain_at + (this->location, + _("symbol %s is used, but is not defined as a token and has no rules"), + this->tag); + this->class = nterm_sym; + this->number = nvars++; + } + + return TRUE; +} + + +/*-------------------------------------------------------------------. +| Declare the new SYMBOL. Make it an alias of SYMVAL, and type them | +| with TYPENAME. | +`-------------------------------------------------------------------*/ + +void +symbol_make_alias (symbol_t *symbol, symbol_t *symval, location_t loc) +{ + if (symval->alias) + warn_at (loc, _("symbol `%s' used more than once as a literal string"), + symval->tag); + else if (symbol->alias) + warn_at (loc, _("symbol `%s' given more than one literal string"), + symbol->tag); + else + { + symval->class = token_sym; + symval->user_token_number = symbol->user_token_number; + symbol->user_token_number = USER_NUMBER_ALIAS; + symval->alias = symbol; + symbol->alias = symval; + /* symbol and symval combined are only one symbol */ + nsyms--; + ntokens--; + assert (ntokens == symbol->number || ntokens == symval->number); + symbol->number = symval->number = + (symval->number < symbol->number) ? symval->number : symbol->number; + } +} + + +/*---------------------------------------------------------. +| Check that THIS, and its alias, have same precedence and | +| associativity. | +`---------------------------------------------------------*/ + +static bool +symbol_check_alias_consistence (symbol_t *this) +{ + /* Check only those who _are_ the aliases. */ + if (this->alias && this->user_token_number == USER_NUMBER_ALIAS) + { + if (this->prec != this->alias->prec) { - firstsymbol = bp; - lastsymbol = bp; + if (this->prec != 0 && this->alias->prec != 0) + complain_at (this->alias->location, + _("conflicting precedences for %s and %s"), + this->tag, this->alias->tag); + if (this->prec != 0) + this->alias->prec = this->prec; + else + this->prec = this->alias->prec; } - else + + if (this->assoc != this->alias->assoc) { - lastsymbol->next = bp; - lastsymbol = bp; + if (this->assoc != undef_assoc && this->alias->assoc != undef_assoc) + complain_at (this->alias->location, + _("conflicting associativities for %s (%s) and %s (%s)"), + this->tag, assoc_to_string (this->assoc), + this->alias->tag, assoc_to_string (this->alias->assoc)); + if (this->assoc != undef_assoc) + this->alias->assoc = this->assoc; + else + this->assoc = this->alias->assoc; } + } + return TRUE; +} + - symtab[hashval] = bp; +/*-------------------------------------------------------------------. +| Assign a symbol number, and write the definition of the token name | +| into FDEFINES. Put in SYMBOLS. | +`-------------------------------------------------------------------*/ + +static bool +symbol_pack (symbol_t *this) +{ + if (this->class == nterm_sym) + { + this->number += ntokens; + } + else if (this->alias) + { + /* This symbol and its alias are a single token defn. + Allocate a tokno, and assign to both check agreement of + prec and assoc fields and make both the same */ + if (this->number == NUMBER_UNDEFINED) + { + if (this == endtoken || this->alias == endtoken) + this->number = this->alias->number = 0; + else + { + assert (this->alias->number != NUMBER_UNDEFINED); + this->number = this->alias->number; + } + } + /* Do not do processing below for USER_NUMBER_ALIASs. */ + if (this->user_token_number == USER_NUMBER_ALIAS) + return TRUE; + } + else /* this->class == token_sym */ + { + assert (this->number != NUMBER_UNDEFINED); } - return bp; + symbols[this->number] = this; + return TRUE; } + + +/*--------------------------------------------------. +| Put THIS in TOKEN_TRANSLATIONS if it is a token. | +`--------------------------------------------------*/ + +static bool +symbol_translation (symbol_t *this) +{ + /* Non-terminal? */ + if (this->class == token_sym + && this->user_token_number != USER_NUMBER_ALIAS) + { + /* A token which translation has already been set? */ + if (token_translations[this->user_token_number] != undeftoken->number) + complain_at (this->location, + _("tokens %s and %s both assigned number %d"), + symbols[token_translations[this->user_token_number]]->tag, + this->tag, this->user_token_number); + + token_translations[this->user_token_number] = this->number; + } + + return TRUE; +} + + +/*----------------------. +| A symbol hash table. | +`----------------------*/ + +/* Initial capacity of symbols hash table. */ +#define HT_INITIAL_CAPACITY 257 + +static struct hash_table *symbol_table = NULL; + +static bool +hash_compare_symbol_t (const symbol_t *m1, const symbol_t *m2) +{ + return strcmp (m1->tag, m2->tag) ? FALSE : TRUE; +} + +static unsigned int +hash_symbol_t (const symbol_t *m, unsigned int tablesize) +{ + return hash_string (m->tag, tablesize); +} + + +/*-------------------------------. +| Create the symbol hash table. | +`-------------------------------*/ + +void +symbols_new (void) +{ + symbol_table = hash_initialize (HT_INITIAL_CAPACITY, + NULL, + (Hash_hasher) hash_symbol_t, + (Hash_comparator) hash_compare_symbol_t, + (Hash_data_freer) symbol_free); +} + + +/*----------------------------------------------------------------. +| Find the symbol named KEY, and return it. If it does not exist | +| yet, create it. | +`----------------------------------------------------------------*/ + +symbol_t * +symbol_get (const char *key, location_t location) +{ + symbol_t probe; + symbol_t *entry; + + /* Keep the symbol in a printable form. */ + key = quotearg_style (escape_quoting_style, key); + *(char const **) &probe.tag = key; + entry = hash_lookup (symbol_table, &probe); + + if (!entry) + { + /* First insertion in the hash. */ + entry = symbol_new (key, location); + hash_insert (symbol_table, entry); + } + return entry; +} + + +/*------------------------------------------------------------------. +| Generate a dummy nonterminal, whose name cannot conflict with the | +| user's names. | +`------------------------------------------------------------------*/ + +symbol_t * +dummy_symbol_get (location_t location) +{ + /* Incremented for each generated symbol. */ + static int dummy_count = 0; + static char buf[256]; + + symbol_t *sym; + + sprintf (buf, "@%d", ++dummy_count); + sym = symbol_get (buf, location); + sym->class = nterm_sym; + sym->number = nvars++; + return sym; +} + + +/*-------------------. +| Free the symbols. | +`-------------------*/ + +void +symbols_free (void) +{ + hash_free (symbol_table); + free (symbols); +} + + +/*---------------------------------------------------------------. +| Look for undefined symbols, report an error, and consider them | +| terminals. | +`---------------------------------------------------------------*/ + +void +symbols_do (symbol_processor processor, void *processor_data) +{ + hash_do_for_each (symbol_table, + (Hash_processor) processor, + processor_data); +} + + +/*--------------------------------------------------------------. +| Check that all the symbols are defined. Report any undefined | +| symbols and consider them nonterminals. | +`--------------------------------------------------------------*/ + void -free_symtab (void) +symbols_check_defined (void) { + symbols_do (symbol_check_defined, NULL); +} + +/*------------------------------------------------------------------. +| Set TOKEN_TRANSLATIONS. Check that no two symbols share the same | +| number. | +`------------------------------------------------------------------*/ + +static void +symbols_token_translations_init (void) +{ + int num_256_available_p = TRUE; int i; - bucket *bp, *bptmp; /* JF don't use ptr after free */ - for (i = 0; i < TABSIZE; 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) { - bp = symtab[i]; - while (bp) + symbol_t *this = symbols[i]; + if (this->user_token_number != USER_NUMBER_UNDEFINED) { - bptmp = bp->link; -#if 0 - /* This causes crashes because one string can appear more - than once. */ - if (bp->type_name) - XFREE (bp->type_name); -#endif - XFREE (bp); - bp = bptmp; + 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; } } - XFREE (symtab); + + /* 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_t *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 = XCALLOC (symbol_number_t, max_user_token_number + 1); + + /* 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, 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 = XCALLOC (symbol_t *, nsyms); + + symbols_do (symbol_check_alias_consistence, NULL); + symbols_do (symbol_pack, NULL); + + 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); }