X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/b29b2ed5600cd819f4237b7b050288f6e19d102d..233a88ad114676df64ab410a03a73e50e5f4365a:/src/symtab.c diff --git a/src/symtab.c b/src/symtab.c index 455e74e2..2a542051 100644 --- a/src/symtab.c +++ b/src/symtab.c @@ -1,5 +1,7 @@ -/* Symbol table manager for Bison, - Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc. +/* Symbol table manager for Bison. + + Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004 Free Software + Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -20,132 +22,576 @@ #include "system.h" -#include "symtab.h" -#include "gram.h" +#include +#include -bucket *firstsymbol; -static bucket *lastsymbol; -static bucket **symtab; - -static int -hash (const char *key) -{ - const char *cp; - int k; +#include "complain.h" +#include "gram.h" +#include "symtab.h" - cp = key; - k = 0; - while (*cp) - k = ((k << 1) ^ (*cp++)) & 0x3fff; +/*------------------------. +| Distinguished symbols. | +`------------------------*/ - return k % TABSIZE; -} +symbol *errtoken = NULL; +symbol *undeftoken = NULL; +symbol *endtoken = NULL; +symbol *accept = NULL; +symbol *startsymbol = NULL; +location startsymbol_location; -/*--------------------------------------------------------------. -| Create a new symbol, named TAG, which hash value is HASHVAL. | -`--------------------------------------------------------------*/ +/*---------------------------------. +| Create a new symbol, named TAG. | +`---------------------------------*/ -static bucket * -bucket_new (const char *tag, int hashval) +static symbol * +symbol_new (uniqstr tag, location loc) { - bucket *res = XMALLOC (bucket, 1); + symbol *res = MALLOC (res, 1); + + uniqstr_assert (tag); + res->tag = tag; + res->location = loc; - res->link = symtab[hashval]; - res->next = NULL; - res->tag = xstrdup (tag); res->type_name = NULL; - res->value = 0; + res->destructor = NULL; + res->printer = NULL; + + res->number = NUMBER_UNDEFINED; res->prec = 0; - res->assoc = right_assoc; - res->user_token_number = SUNDEF; + res->assoc = undef_assoc; + res->user_token_number = USER_NUMBER_UNDEFINED; + res->alias = NULL; res->class = unknown_sym; nsyms++; - return res; } +/*-----------------------------------------------------------------. +| Set the TYPE_NAME associated with SYM. Does nothing if passed 0 | +| as TYPE_NAME. | +`-----------------------------------------------------------------*/ + void -tabinit (void) +symbol_type_set (symbol *sym, uniqstr type_name, location loc) { - symtab = XCALLOC (bucket *, TABSIZE); + if (type_name) + { + if (sym->type_name) + complain_at (loc, _("type redeclaration for %s"), sym->tag); + uniqstr_assert (type_name); + sym->type_name = type_name; + } +} - firstsymbol = NULL; - lastsymbol = NULL; + +/*------------------------------------------------------------------. +| Set the DESTRUCTOR associated with SYM. Do nothing if passed 0. | +`------------------------------------------------------------------*/ + +void +symbol_destructor_set (symbol *sym, char *destructor, location loc) +{ + if (destructor) + { + if (sym->destructor) + complain_at (loc, _("%s redeclaration for %s"), + "%destructor", sym->tag); + sym->destructor = destructor; + sym->destructor_location = loc; + } } -/*----------------------------------------------------------------. -| Find the symbol named KEY, and return it. If it does not exist | -| yet, create it. | -`----------------------------------------------------------------*/ +/*---------------------------------------------------------------. +| Set the PRINTER associated with SYM. Do nothing if passed 0. | +`---------------------------------------------------------------*/ + +void +symbol_printer_set (symbol *sym, char *printer, location loc) +{ + if (printer) + { + if (sym->printer) + complain_at (loc, _("%s redeclaration for %s"), + "%printer", sym->tag); + sym->printer = printer; + sym->printer_location = loc; + } +} + + +/*-----------------------------------------------------------------. +| 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) + complain_at (loc, _("redefining precedence of %s"), sym->tag); + sym->prec = prec; + sym->assoc = a; + } + + /* Only terminals have a precedence. */ + symbol_class_set (sym, token_sym, loc); +} + + +/*------------------------------------. +| Set the CLASS associated with SYM. | +`------------------------------------*/ + +void +symbol_class_set (symbol *sym, symbol_class class, location loc) +{ + if (sym->class != unknown_sym && sym->class != class) + complain_at (loc, _("symbol %s redefined"), sym->tag); + + 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; +} + + +/*------------------------------------------------. +| Set the USER_TOKEN_NUMBER associated with SYM. | +`------------------------------------------------*/ -bucket * -getsym (const char *key) +void +symbol_user_token_number_set (symbol *sym, int user_token_number, location loc) { - int hashval; - bucket *bp; - int found; + if (sym->class != token_sym) + abort (); - hashval = hash (key); - bp = symtab[hashval]; + if (sym->user_token_number != USER_NUMBER_UNDEFINED + && sym->user_token_number != user_token_number) + complain_at (loc, _("redefining user token number of %s"), sym->tag); - found = 0; - while (bp != NULL && found == 0) + sym->user_token_number = user_token_number; + /* User defined $end token? */ + if (user_token_number == 0) { - if (strcmp (key, bp->tag) == 0) - found = 1; - else - bp = bp->link; + endtoken = sym; + endtoken->number = 0; + /* It is always mapped to 0, so it was already counted in + NTOKENS. */ + --ntokens; } +} + - if (found == 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) { - bp = bucket_new (key, hashval); + 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++; + } - if (firstsymbol == NULL) + return true; +} + +static bool +symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED) +{ + return symbol_check_defined (sym); +} + + +/*------------------------------------------------------------------. +| Declare the new symbol SYM. Make it an alias of SYMVAL, and type | +| SYMVAL with SYM's type. | +`------------------------------------------------------------------*/ + +void +symbol_make_alias (symbol *sym, symbol *symval, location loc) +{ + if (symval->alias) + warn_at (loc, _("symbol `%s' used more than once as a literal string"), + symval->tag); + else if (sym->alias) + warn_at (loc, _("symbol `%s' given more than one literal string"), + sym->tag); + else + { + symval->class = token_sym; + symval->user_token_number = sym->user_token_number; + sym->user_token_number = USER_NUMBER_ALIAS; + symval->alias = sym; + sym->alias = symval; + /* sym and symval combined are only one symbol. */ + nsyms--; + ntokens--; + if (ntokens != sym->number && ntokens != symval->number) + abort (); + sym->number = symval->number = + (symval->number < sym->number) ? symval->number : sym->number; + symbol_type_set (symval, sym->type_name, loc); + } +} + + +/*---------------------------------------------------------. +| Check that THIS, and its alias, have same precedence and | +| associativity. | +`---------------------------------------------------------*/ + +static inline bool +symbol_check_alias_consistency (symbol *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; +} + +static bool +symbol_check_alias_consistency_processor (void *this, + void *null ATTRIBUTE_UNUSED) +{ + return symbol_check_alias_consistency (this); +} + - symtab[hashval] = bp; +/*-------------------------------------------------------------------. +| Assign a symbol number, and write the definition of the token name | +| into FDEFINES. Put in SYMBOLS. | +`-------------------------------------------------------------------*/ + +static inline bool +symbol_pack (symbol *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 + { + if (this->alias->number == NUMBER_UNDEFINED) + abort (); + this->number = this->alias->number; + } + } + /* Do not do processing below for USER_NUMBER_ALIASes. */ + if (this->user_token_number == USER_NUMBER_ALIAS) + return true; + } + else /* this->class == token_sym */ + { + if (this->number == NUMBER_UNDEFINED) + abort (); } - return bp; + symbols[this->number] = this; + return true; } +static bool +symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED) +{ + return symbol_pack (this); +} + + + + +/*--------------------------------------------------. +| 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_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; +} + +static bool +symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED) +{ + return symbol_translation (this); +} + + +/*----------------------. +| A symbol hash table. | +`----------------------*/ + +/* Initial capacity of symbols hash table. */ +#define HT_INITIAL_CAPACITY 257 + +static struct hash_table *symbol_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 bool +hash_symbol_comparator (void const *m1, void const *m2) +{ + return hash_compare_symbol (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 size_t +hash_symbol_hasher (void const *m, size_t tablesize) +{ + return hash_symbol (m, tablesize); +} + + +/*-------------------------------. +| Create the symbol hash table. | +`-------------------------------*/ void -free_symtab (void) +symbols_new (void) { + symbol_table = hash_initialize (HT_INITIAL_CAPACITY, + NULL, + hash_symbol_hasher, + hash_symbol_comparator, + free); +} + + +/*----------------------------------------------------------------. +| Find the symbol named KEY, and return it. If it does not exist | +| yet, create it. | +`----------------------------------------------------------------*/ + +symbol * +symbol_get (const char *key, location loc) +{ + symbol probe; + symbol *entry; + + /* Keep the symbol in a printable form. */ + key = uniqstr_new (quotearg_style (escape_quoting_style, key)); + probe.tag = key; + entry = hash_lookup (symbol_table, &probe); + + if (!entry) + { + /* First insertion in the hash. */ + entry = symbol_new (key, loc); + hash_insert (symbol_table, entry); + } + return entry; +} + + +/*------------------------------------------------------------------. +| 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; +} + + +/*-------------------. +| Free the symbols. | +`-------------------*/ + +void +symbols_free (void) +{ + hash_free (symbol_table); + free (symbols); +} + + +/*---------------------------------------------------------------. +| Look for undefined symbols, report an error, and consider them | +| terminals. | +`---------------------------------------------------------------*/ + +static void +symbols_do (Hash_processor processor, void *processor_data) +{ + hash_do_for_each (symbol_table, processor, 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; - 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 *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->tag); - 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 *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; + } + + CALLOC (token_translations, 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_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) +{ + CALLOC (symbols, nsyms); + + symbols_do (symbol_check_alias_consistency_processor, NULL); + symbols_do (symbol_pack_processor, 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); }