int lineno;
static symbol_list *grammar = NULL;
static int start_flag = 0;
-static symbol_t *startval = NULL;
-
-/* Nonzero if components of semantic values are used, implying
- they must be unions. */
-static int value_components_used;
/* Nonzero if %union has been seen. */
static int typed = 0;
/* Incremented for each %left, %right or %nonassoc seen */
static int lastprec = 0;
-symbol_t *errtoken = NULL;
-symbol_t *undeftoken = NULL;
-symbol_t *eoftoken = NULL;
-symbol_t *axiom = NULL;
-
static symbol_list *
symbol_list_new (symbol_t *sym)
{
return res;
}
-/*------------------------.
-| Operations on symbols. |
-`------------------------*/
-
-
-/*-----------------------------------------------------------.
-| 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
- (_("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;
-}
-
-
-/*-------------------------------------------------------------------.
-| Assign a symbol number, and write the definition of the token name |
-| into FDEFINES. Put in SYMBOLS. |
-`-------------------------------------------------------------------*/
-
-static bool
-symbol_make_alias (symbol_t *symbol, char *typename)
-{
- if (symval->alias)
- warn (_("symbol `%s' used more than once as a literal string"),
- symval->tag);
- else if (symbol->alias)
- warn (_("symbol `%s' given more than one literal string"),
- symbol->tag);
- else
- {
- symval->class = token_sym;
- symval->type_name = typename;
- 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;
- }
-
- return TRUE;
-}
-
-/*---------------------------------------------------------.
-| 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)
- {
- if (this->prec != 0 && this->alias->prec != 0)
- complain (_("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;
- }
-
- if (this->assoc != this->alias->assoc)
- {
- if (this->assoc != 0 && this->alias->assoc != 0)
- complain (_("conflicting assoc values for %s and %s"),
- this->tag, this->alias->tag);
- if (this->assoc != 0)
- this->alias->assoc = this->assoc;
- else
- this->assoc = this->alias->assoc;
- }
- }
- return TRUE;
-}
-
-
-/*-------------------------------------------------------------------.
-| 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 == eoftoken || this->alias == eoftoken)
- 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);
- }
-
- 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 (_("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;
-}
-\f
-
/*===================\
| Low level lexing. |
\===================*/
{
read_type_name (fin);
type_name = token_buffer;
- value_components_used = 1;
c = getc (fin);
}
}
-/*-------------------------------------------------------------------.
-| Parse what comes after %token or %nterm. For %token, WHAT_IS is |
-| token_sym and WHAT_IS_NOT is nterm_sym. For %nterm, the arguments |
-| are reversed. |
-`-------------------------------------------------------------------*/
+/*------------------------------------------.
+| Parse what comes after %token or %nterm. |
+`------------------------------------------*/
static void
-parse_token_decl (symbol_class what_is, symbol_class what_is_not)
+parse_token_decl (symbol_class class)
{
token_t token = tok_undef;
char *typename = NULL;
fatal (_("Premature EOF after %s"), token_buffer);
token = lex ();
- if (token == tok_comma)
+ switch (token)
{
+ case tok_comma:
symbol = NULL;
- continue;
- }
- if (token == tok_typename)
- {
+ break;
+
+ case tok_typename:
typename = xstrdup (token_buffer);
- value_components_used = 1;
symbol = NULL;
- }
- else if (token == tok_identifier && *symval->tag == '\"' && symbol)
- {
- symbol_make_alias (symbol, typename);
- symbol = NULL;
- }
- else if (token == tok_identifier)
- {
- int oldclass = symval->class;
- symbol = symval;
-
- if (symbol->class == what_is_not)
- complain (_("symbol %s redefined"), symbol->tag);
- symbol->class = what_is;
- if (what_is == nterm_sym && oldclass != nterm_sym)
- symbol->number = nvars++;
- if (what_is == token_sym && symbol->number == NUMBER_UNDEFINED)
- symbol->number = ntokens++;
-
- if (typename)
+ break;
+
+ case tok_identifier:
+ if (*symval->tag == '\"' && symbol)
{
- if (symbol->type_name == NULL)
- symbol->type_name = typename;
- else if (strcmp (typename, symbol->type_name) != 0)
- complain (_("type redeclaration for %s"), symbol->tag);
+ symbol_make_alias (symbol, symval, typename);
+ symbol = NULL;
}
- }
- else if (symbol && token == tok_number)
- {
- symbol->user_token_number = numval;
- /* User defined EOF token? */
- if (numval == 0)
+ else
{
- eoftoken = symbol;
- eoftoken->number = 0;
- /* It is always mapped to 0, so it was already counted in
- NTOKENS. */
- --ntokens;
+ symbol = symval;
+ symbol_class_set (symbol, class);
+ if (typename)
+ symbol_type_set (symbol, typename);
}
- }
- else
- {
+ break;
+
+ case tok_number:
+ symbol_user_token_number_set (symbol, numval);
+ break;
+
+ default:
complain (_("`%s' is invalid in %s"),
token_buffer,
- (what_is == token_sym) ? "%token" : "%nterm");
+ (class == token_sym) ? "%token" : "%nterm");
skip_to_char ('%');
}
}
else
{
start_flag = 1;
- startval = symval;
+ startsymbol = symval;
}
}
switch (t)
{
-
case tok_comma:
case tok_semicolon:
break;
case tok_identifier:
- if (symval->type_name == NULL)
- symval->type_name = name;
- else if (strcmp (name, symval->type_name) != 0)
- complain (_("type redeclaration for %s"), symval->tag);
-
+ symbol_type_set (symval, name);
break;
default:
break;
case tok_identifier:
- if (symval->prec != 0)
- complain (_("redefining precedence of %s"), symval->tag);
- symval->prec = lastprec;
- symval->assoc = assoc;
- if (symval->class == nterm_sym)
- complain (_("symbol %s redefined"), symval->tag);
- if (symval->number == NUMBER_UNDEFINED)
- {
- symval->number = ntokens++;
- symval->class = token_sym;
- }
+ symbol_class_set (symval, token_sym);
+ symbol_precedence_set (symval, lastprec, assoc);
if (name)
- { /* record the type, if one is specified */
- if (symval->type_name == NULL)
- symval->type_name = name;
- else if (strcmp (name, symval->type_name) != 0)
- complain (_("type redeclaration for %s"), symval->tag);
- }
+ symbol_type_set (symval, name);
break;
case tok_number:
if (prev == tok_identifier)
{
- symval->user_token_number = numval;
+ symbol_user_token_number_set (symval, numval);
}
else
{
}
-/*-------------------------------------------------------------------.
-| Parse what comes after %thong. the full syntax is |
-| |
-| %thong <type> token number literal |
-| |
-| the <type> or number may be omitted. The number specifies the |
-| user_token_number. |
-| |
-| Two symbols are entered in the table, one for the token symbol and |
-| one for the literal. Both are given the <type>, if any, from the |
-| declaration. The ->user_token_number of the first is |
-| USER_NUMBER_ALIAS and the ->user_token_number of the second is set |
-| to the number, if any, from the declaration. The two symbols are |
-| linked via pointers in their ->alias fields. |
-| |
-| During OUTPUT_DEFINES_TABLE, the symbol is reported thereafter, |
-| only the literal string is retained it is the literal string that |
-| is output to yytname |
-`-------------------------------------------------------------------*/
-
-static void
-parse_thong_decl (void)
-{
- token_t token;
- symbol_t *symbol;
- char *typename = 0;
- int usrtoknum = USER_NUMBER_UNDEFINED;
-
- token = lex (); /* fetch typename or first token */
- if (token == tok_typename)
- {
- typename = xstrdup (token_buffer);
- value_components_used = 1;
- token = lex (); /* fetch first token */
- }
-
- /* process first token */
-
- if (token != tok_identifier)
- {
- complain (_("unrecognized item %s, expected an identifier"),
- token_buffer);
- skip_to_char ('%');
- return;
- }
- symval->class = token_sym;
- symval->type_name = typename;
- symval->user_token_number = USER_NUMBER_ALIAS;
- symbol = symval;
-
- token = lex (); /* get number or literal string */
-
- if (token == tok_number)
- {
- usrtoknum = numval;
- token = lex (); /* okay, did number, now get literal */
- }
-
- /* process literal string token */
-
- if (token != tok_identifier || *symval->tag != '\"')
- {
- complain (_("expected string constant instead of %s"), token_buffer);
- skip_to_char ('%');
- return;
- }
- symval->class = token_sym;
- symval->type_name = typename;
- symval->user_token_number = usrtoknum;
-
- symval->alias = symbol;
- symbol->alias = symval;
-
- /* symbol and symval combined are only one symbol. */
- nsyms--;
-}
-
-
static void
parse_muscle_decl (void)
{
break;
case tok_token:
- parse_token_decl (token_sym, nterm_sym);
+ parse_token_decl (token_sym);
break;
case tok_nterm:
- parse_token_decl (nterm_sym, token_sym);
+ parse_token_decl (nterm_sym);
break;
case tok_type:
parse_expect_decl ();
break;
- case tok_thong:
- parse_thong_decl ();
- break;
-
case tok_left:
parse_assoc_decl (left_assoc);
break;
| in the rules section. |
`-------------------------------------------------------------------*/
+/* The (currently) last symbol of GRAMMAR. */
+symbol_list *grammar_end = NULL;
+
+/* Append S to the GRAMMAR. */
+static void
+grammar_symbol_append (symbol_t *s)
+{
+ symbol_list *p = symbol_list_new (s);
+
+ if (grammar_end)
+ grammar_end->next = p;
+ else
+ grammar = p;
+
+ grammar_end = p;
+}
+
+/* The rule currently being defined, and the previous rule. Point to
+ the first symbol of each list: their lhs. */
+symbol_list *current_rule = NULL;
+symbol_list *previous_rule = NULL;
+
+
+/* Create a new rule for LHS in to the GRAMMAR. */
+
+static void
+grammar_rule_begin (symbol_t *lhs)
+{
+ if (!start_flag)
+ {
+ startsymbol = lhs;
+ start_flag = 1;
+ }
+
+ /* Start a new rule and record its lhs. */
+ ++nrules;
+ ++nritems;
+
+ previous_rule = grammar_end;
+ grammar_symbol_append (lhs);
+ current_rule = grammar_end;
+
+ /* Mark the rule's lhs as a nonterminal if not already so. */
+
+ if (lhs->class == unknown_sym)
+ {
+ lhs->class = nterm_sym;
+ lhs->number = nvars;
+ ++nvars;
+ }
+ else if (lhs->class == token_sym)
+ complain (_("rule given for %s, which is a token"), lhs->tag);
+}
+
+/* The previous action turns out the be a mid-rule action. Attach it
+ to the current rule, i.e., create a dummy symbol, attach it this
+ mid-rule action, and append this dummy nonterminal to the current
+ rule. */
+
+static void
+grammar_midrule_action (void)
+{
+ /* Since the action was written out with this rule's number, we must
+ give the new rule this number by inserting the new rule before
+ it. */
+
+ /* Make a dummy nonterminal, a gensym. */
+ symbol_t *sdummy = gensym ();
+ symbol_list *midrule_action = symbol_list_new (sdummy);
+
+ /* Make a new rule, whose body is empty, before the current one, so
+ that the action just read can belong to it. */
+ ++nrules;
+ ++nritems;
+ /* Attach its lineno to that of the host rule. */
+ midrule_action->line = current_rule->line;
+ /* Move the action from the host rule to this one. */
+ midrule_action->action = current_rule->action;
+ midrule_action->action_line = current_rule->action_line;
+ current_rule->action = NULL;
+
+ if (previous_rule)
+ previous_rule->next = midrule_action;
+ else
+ grammar = midrule_action;
+
+ /* End of the rule. */
+ previous_rule = symbol_list_new (NULL);
+ previous_rule->next = current_rule;
+
+ midrule_action->next = previous_rule;
+
+ /* Insert the dummy generated by that rule into this rule. */
+ ++nritems;
+ grammar_symbol_append (sdummy);
+}
+
+
static void
readgram (void)
{
token_t t;
symbol_t *lhs = NULL;
- symbol_list *p = NULL;
- symbol_list *p1 = NULL;
-
- /* Points to first symbol_list of current rule. its symbol is the
- lhs of the rule. */
- symbol_list *crule = NULL;
- /* Points to the symbol_list preceding crule. */
- symbol_list *crule1 = NULL;
t = lex ();
{
lhs = symval;
- if (!start_flag)
- {
- startval = lhs;
- start_flag = 1;
- }
-
t = lex ();
if (t != tok_colon)
{
unlex (t);
}
}
-
if (nrules == 0 && t == tok_bar)
{
complain (_("grammar starts with vertical bar"));
lhs = symval; /* BOGUS: use a random symval */
}
- /* start a new rule and record its lhs. */
-
- ++nrules;
- ++nritems;
-
- p = symbol_list_new (lhs);
-
- crule1 = p1;
- if (p1)
- p1->next = p;
- else
- grammar = p;
-
- p1 = p;
- crule = p;
-
- /* mark the rule's lhs as a nonterminal if not already so. */
-
- if (lhs->class == unknown_sym)
- {
- lhs->class = nterm_sym;
- lhs->number = nvars;
- ++nvars;
- }
- else if (lhs->class == token_sym)
- complain (_("rule given for %s, which is a token"), lhs->tag);
+ grammar_rule_begin (lhs);
/* read the rhs of the rule. */
for (;;)
if (t == tok_prec)
{
t = lex ();
- crule->ruleprec = symval;
+ current_rule->ruleprec = symval;
t = lex ();
}
non-terminal. */
if (action_flag)
{
- /* Since the action was written out with this rule's
- number, we must give the new rule this number by
- inserting the new rule before it. */
-
- /* Make a dummy nonterminal, a gensym. */
- symbol_t *sdummy = gensym ();
-
- /* Make a new rule, whose body is empty, before the
- current one, so that the action just read can
- belong to it. */
- ++nrules;
- ++nritems;
- p = symbol_list_new (sdummy);
- /* Attach its lineno to that of the host rule. */
- p->line = crule->line;
- /* Move the action from the host rule to this one. */
- p->action = crule->action;
- p->action_line = crule->action_line;
- crule->action = NULL;
-
- if (crule1)
- crule1->next = p;
- else
- grammar = p;
- /* End of the rule. */
- crule1 = symbol_list_new (NULL);
- crule1->next = crule;
-
- p->next = crule1;
-
- /* Insert the dummy generated by that rule into this
- rule. */
- ++nritems;
- p = symbol_list_new (sdummy);
- p1->next = p;
- p1 = p;
-
+ grammar_midrule_action ();
action_flag = 0;
}
if (t == tok_identifier)
{
++nritems;
- p = symbol_list_new (symval);
- p1->next = p;
- p1 = p;
+ grammar_symbol_append (symval);
}
else /* handle an action. */
{
- parse_action (crule, rulelength);
+ parse_action (current_rule, rulelength);
action_flag = 1;
++xactions; /* JF */
}
} /* end of read rhs of rule */
/* Put an empty link in the list to mark the end of this rule */
- p = symbol_list_new (NULL);
- p1->next = p;
- p1 = p;
+ grammar_symbol_append (NULL);
if (t == tok_prec)
{
complain (_("two @prec's in a row"));
t = lex ();
- crule->ruleprec = symval;
+ current_rule->ruleprec = symval;
t = lex ();
}
/* This case never occurs -wjh */
if (action_flag)
complain (_("two actions at end of one rule"));
- parse_action (crule, rulelength);
+ parse_action (current_rule, rulelength);
action_flag = 1;
++xactions; /* -wjh */
t = lex ();
fatal (_("no rules in the input grammar"));
/* Report any undefined symbols and consider them nonterminals. */
- symbols_do (symbol_check_defined, NULL);
+ symbols_check_defined ();
/* Insert the initial rule, which line is that of the first rule
(not that of the start symbol):
axiom: %start EOF. */
- p = symbol_list_new (axiom);
- p->line = grammar->line;
- p->next = symbol_list_new (startval);
- p->next->next = symbol_list_new (eoftoken);
- p->next->next->next = symbol_list_new (NULL);
- p->next->next->next->next = grammar;
- nrules += 1;
- nritems += 3;
- grammar = p;
- startval = axiom;
+ {
+ symbol_list *p = symbol_list_new (axiom);
+ p->line = grammar->line;
+ p->next = symbol_list_new (startsymbol);
+ p->next->next = symbol_list_new (eoftoken);
+ p->next->next->next = symbol_list_new (NULL);
+ p->next->next->next->next = grammar;
+ nrules += 1;
+ nritems += 3;
+ grammar = p;
+ }
if (nsyms > SHRT_MAX)
fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
}
\f
-/*------------------------------------------------------------------.
-| Set TOKEN_TRANSLATIONS. Check that no two symbols share the same |
-| number. |
-`------------------------------------------------------------------*/
-
-static void
-token_translations_init (void)
-{
- int 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_t *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_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 (token_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. |
-`----------------------------------------------------------------*/
-
-static void
-packsymbols (void)
-{
- symbols = XCALLOC (symbol_t *, nsyms);
-
- symbols_do (symbol_check_alias_consistence, NULL);
- symbols_do (symbol_pack, NULL);
-
- token_translations_init ();
-
- if (startval->class == unknown_sym)
- fatal (_("the start symbol %s is undefined"), startval->tag);
- else if (startval->class == token_sym)
- fatal (_("the start symbol %s is a token"), startval->tag);
-
- start_symbol = startval->number;
-}
-
-
/*---------------------------------------------------------------.
| Convert the rules into the representation using RRHS, RLHS and |
| RITEM. |
p = p->next;
while (p && p->sym)
{
- /* item_number_t = token_number_t.
+ /* item_number_t = symbol_number_t.
But the former needs to contain more: negative rule numbers. */
- ritem[itemno++] = token_number_as_item_number (p->sym->number);
+ ritem[itemno++] = symbol_number_as_item_number (p->sym->number);
/* A rule gets by default the precedence and associativity
of the last token in it. */
if (p->sym->class == token_sym)
/* Assign the symbols their symbol numbers. Write #defines for the
token symbols into FDEFINES if requested. */
- packsymbols ();
+ symbols_pack ();
/* Convert the grammar into the format described in gram.h. */
packgram ();
projects / bison.git / blobdiff