/* Input parser for Bison
Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000-2003, 2005-2007,
- 2009-2012 Free Software Foundation, Inc.
+ 2009-2015 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
return true;
if ((s->midrule && s->midrule->action_props.is_value_used)
|| (s->midrule_parent_rule
- && symbol_list_n_get (s->midrule_parent_rule,
- s->midrule_parent_rhs_index)
- ->action_props.is_value_used))
+ && (symbol_list_n_get (s->midrule_parent_rule,
+ s->midrule_parent_rhs_index)
+ ->action_props.is_value_used)))
{
*midrule_warning = true;
return true;
bool midrule_warning = false;
if (!l->action_props.is_value_used
&& symbol_should_be_used (l, &midrule_warning)
- /* The default action, $$ = $1, `uses' both. */
+ /* The default action, $$ = $1, 'uses' both. */
&& (r->action_props.code || (n != 0 && n != 1)))
{
warnings warn_flag = midrule_warning ? Wmidrule_values : Wother;
if (n)
- complain (&r->location, warn_flag, _("unused value: $%d"), n);
+ complain (&l->location, warn_flag, _("unused value: $%d"), n);
else
- complain (&r->location, warn_flag, _("unset value: $$"));
+ complain (&l->location, warn_flag, _("unset value: $$"));
}
}
}
+ /* Check that %empty => empty rule. */
+ if (r->percent_empty_loc.start.file
+ && r->next && r->next->content.sym)
+ complain (&r->percent_empty_loc, complaint,
+ _("%%empty on non-empty rule"));
+
+ /* Check that empty rule => %empty. */
+ if (!(r->next && r->next->content.sym)
+ && !r->midrule_parent_rule
+ && !r->percent_empty_loc.start.file)
+ complain (&r->location, Wempty_rule, _("empty rule without %%empty"));
+
/* See comments in grammar_current_rule_prec_set for how POSIX
mandates this complaint. It's only for identifiers, so skip
it for char literals and strings, which are always tokens. */
token. */
symbol_class_set (precsym, token_sym, loc, false);
if (current_rule->ruleprec)
- complain (&loc, complaint, _("only one %s allowed per rule"), "%prec");
- current_rule->ruleprec = precsym;
+ duplicate_directive ("%prec",
+ current_rule->ruleprec->location, loc);
+ else
+ current_rule->ruleprec = precsym;
+}
+
+/* Set %empty for the current rule. */
+
+void
+grammar_current_rule_empty_set (location loc)
+{
+ /* If %empty is used and -Wno-empty-rule is not, then enable
+ -Wempty-rule. */
+ if (warning_is_unset (Wempty_rule))
+ warning_argmatch ("empty-rule", 0, 0);
+ if (current_rule->percent_empty_loc.start.file)
+ duplicate_directive ("%empty",
+ current_rule->percent_empty_loc, loc);
+ else
+ current_rule->percent_empty_loc = loc;
}
/* Attach dynamic precedence DPREC to the current rule. */
complain (&loc, complaint, _("%s must be followed by positive number"),
"%dprec");
else if (current_rule->dprec != 0)
- complain (&loc, complaint, _("only one %s allowed per rule"), "%dprec");
- current_rule->dprec = dprec;
+ duplicate_directive ("%dprec",
+ current_rule->dprec_location, loc);
+ else
+ {
+ current_rule->dprec = dprec;
+ current_rule->dprec_location = loc;
+ }
}
/* Attach a merge function NAME with argument type TYPE to current
complain (&loc, Wother, _("%s affects only GLR parsers"),
"%merge");
if (current_rule->merger != 0)
- complain (&loc, complaint, _("only one %s allowed per rule"), "%merge");
- current_rule->merger = get_merge_function (name);
- current_rule->merger_declaration_location = loc;
+ duplicate_directive ("%merge",
+ current_rule->merger_declaration_location, loc);
+ else
+ {
+ current_rule->merger = get_merge_function (name);
+ current_rule->merger_declaration_location = loc;
+ }
}
/* Attach SYM to the current rule. If needed, move the previous
grammar_midrule_action ();
p = grammar_symbol_append (sym, loc);
if (name)
- assign_named_ref(p, name);
+ assign_named_ref (p, name);
if (sym->status == undeclared || sym->status == used)
sym->status = needed;
}
{
unsigned int itemno = 0;
rule_number ruleno = 0;
- symbol_list *p = grammar;
+ symbol_list *p;
ritem = xnmalloc (nritems + 1, sizeof *ritem);
rules = xnmalloc (nrules, sizeof *rules);
- while (p)
+ for (p = grammar; p; p = p->next)
{
- int rule_length = 0;
symbol *ruleprec = p->ruleprec;
record_merge_function_type (p->merger, p->content.sym->type_name,
p->merger_declaration_location);
rules[ruleno].action_location = p->action_props.location;
rules[ruleno].is_predicate = p->action_props.is_predicate;
- /* If the midrule's $$ is set or its $n is used, remove the `$' from the
+ /* If the midrule's $$ is set or its $n is used, remove the '$' from the
symbol name so that it's a user-defined symbol so that the default
%destructor and %printer apply. */
if (p->midrule_parent_rule
&& (p->action_props.is_value_used
- || symbol_list_n_get (p->midrule_parent_rule,
- p->midrule_parent_rhs_index)
- ->action_props.is_value_used))
+ || (symbol_list_n_get (p->midrule_parent_rule,
+ p->midrule_parent_rhs_index)
+ ->action_props.is_value_used)))
p->content.sym->tag += 1;
/* Don't check the generated rule 0. It has no action, so some rhs
if (p != grammar)
grammar_rule_check (p);
- for (p = p->next; p && p->content.sym; p = p->next)
- {
- ++rule_length;
-
- /* Don't allow rule_length == INT_MAX, since that might
- cause confusion with strtol if INT_MAX == LONG_MAX. */
- if (rule_length == INT_MAX)
- complain (&rules[ruleno].location, fatal, _("rule is too long"));
-
- /* item_number = symbol_number.
- But the former needs to contain more: negative rule numbers. */
- ritem[itemno++] =
- symbol_number_as_item_number (p->content.sym->number);
- /* A rule gets by default the precedence and associativity
- of its last token. */
- if (p->content.sym->class == token_sym && default_prec)
- rules[ruleno].prec = p->content.sym;
- }
+ {
+ size_t rule_length = 0;
+ for (p = p->next; p->content.sym; p = p->next)
+ {
+ ++rule_length;
+
+ /* Don't allow rule_length == INT_MAX, since that might
+ cause confusion with strtol if INT_MAX == LONG_MAX. */
+ if (rule_length == INT_MAX)
+ complain (&rules[ruleno].location, fatal, _("rule is too long"));
+
+ /* item_number = symbol_number.
+ But the former needs to contain more: negative rule numbers. */
+ ritem[itemno++] =
+ symbol_number_as_item_number (p->content.sym->number);
+ /* A rule gets by default the precedence and associativity
+ of its last token. */
+ if (p->content.sym->class == token_sym && default_prec)
+ rules[ruleno].prec = p->content.sym;
+ }
+ }
/* If this rule has a %prec,
the specified symbol's precedence replaces the default. */
aver (itemno < ITEM_NUMBER_MAX);
++ruleno;
aver (ruleno < RULE_NUMBER_MAX);
-
- if (p)
- p = p->next;
}
aver (itemno == nritems);
/* Insert the initial rule, whose line is that of the first rule
(not that of the start symbol):
- accept: %start EOF. */
+ $accept: %start $end. */
{
symbol_list *p = symbol_list_sym_new (accept, empty_location);
p->location = grammar->location;
grammar = p;
}
- aver (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);
+ aver (nsyms <= SYMBOL_NUMBER_MAXIMUM);
+ aver (nsyms == ntokens + nvars);
/* Assign the symbols their symbol numbers. Write #defines for the
token symbols into FDEFINES if requested. */
action type checking.
Before invoking grammar_rule_check (in packgram below) on any rule, make
- sure all actions have already been scanned in order to set `used' flags.
+ sure all actions have already been scanned in order to set 'used' flags.
Otherwise, checking that a midrule's $$ should be set will not always work
properly because the check must forward-reference the midrule's parent
- rule. For the same reason, all the `used' flags must be set before
- checking whether to remove `$' from any midrule symbol name (also in
+ rule. For the same reason, all the 'used' flags must be set before
+ checking whether to remove '$' from any midrule symbol name (also in
packgram). */
{
symbol_list *sym;
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