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Also warn about non-used mid-rule values.

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* src/symlist.h, src/symlist.c (symbol_list): Add a mid_rule
member.
(symbol_list_new): Adjust.
* src/reader.c (symbol_typed_p): New.
(grammar_rule_check): Use it.
(grammar_midrule_action): Bind a mid-rule LHS to its rule.
Check its rule.
* tests/input.at (AT_CHECK_UNUSED_VALUES): New.
Use it.
* tests/actions.at (Exotic Dollars): Adjust.
This commit is contained in:
Akim Demaille
2006-01-04 09:18:37 +00:00
parent 378f4bd846
commit 8486615972
7 changed files with 115 additions and 42 deletions
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26
src/reader.c
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@@ -210,6 +210,20 @@ grammar_current_rule_begin (symbol *lhs, location loc)
}
/*-----------------------------------------------------------------.
| A symbol is typed if it has a declared %type, or if it is a |
| mid-rule symbol (i.e., the generated LHS replacing a mid-rule |
| action) that was assigned to, as in `exp: { $$ = 1; } { $$ = $1; |
| }'. |
`-----------------------------------------------------------------*/
static bool
symbol_typed_p (const symbol_list *s)
{
return (s->sym->type_name
|| s->mid_rule && s->mid_rule->used);
}
/*----------------------------------------------------------------.
| Check that the rule R is properly defined. For instance, there |
| should be no type clash on the default action. |
@@ -251,7 +265,7 @@ grammar_rule_check (const symbol_list *r)
int n = 0;
for (; l && l->sym; l = l->next, ++n)
if (! (l->used
|| !l->sym->type_name
|| !symbol_typed_p (l)
/* The default action, $$ = $1, `uses' both. */
|| (!r->action && (n == 0 || n == 1))))
{
@@ -318,14 +332,16 @@ grammar_midrule_action (void)
grammar = midrule;
/* End the dummy's rule. */
previous_rule_end = symbol_list_new (NULL, dummy_location);
previous_rule_end->next = current_rule;
midrule->next = symbol_list_new (NULL, dummy_location);
grammar_rule_check (midrule);
midrule->next->next = current_rule;
midrule->next = previous_rule_end;
previous_rule_end = midrule->next;
/* Insert the dummy nonterminal replacing the midrule action into
the current rule. */
the current rule. Bind it to its dedicated rule. */
grammar_current_rule_symbol_append (dummy, dummy_location);
grammar_end->mid_rule = midrule;
}
/* Set the precedence symbol of the current rule to PRECSYM. */