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Warn about unset midrule $$ if the corresponding $n is used.

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* src/reader.c (symbol_should_be_used): Check midrule parent rule for
$n usage.
(packgram): Before invoking grammar_rule_check on any rule, make sure
all actions have already been scanned in order to set `used' flags.
Otherwise, checking that a midrule's $$ is set will not always work
properly because the midrule check must forward-reference the midrule's
parent rule.
* tests/input.at (AT_CHECK_UNUSED_VALUES): Extend to check the new
warning.
This commit is contained in:
Joel E. Denny
2006-10-21 02:31:50 +00:00
parent a501eca911
commit 519d000408
3 changed files with 43 additions and 15 deletions
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26
src/reader.c
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@@ -252,7 +252,10 @@ static bool
symbol_should_be_used (symbol_list const *s)
{
return (symbol_destructor_get (s->content.sym)
|| (s->midrule && s->midrule->used));
|| (s->midrule && s->midrule->used)
|| (s->midrule_parent_rule
&& symbol_list_n_get (s->midrule_parent_rule,
s->midrule_parent_rhs_index)->used));
}
/*----------------------------------------------------------------.
@@ -456,6 +459,20 @@ packgram (void)
rules = xnmalloc (nrules, sizeof *rules);
/* Before invoking grammar_rule_check on any rule, make sure
all actions have already been scanned in order to set `used' flags.
Otherwise, checking that a midrule's $$ is set will not always work
properly because the midrule check must forward-reference the midrule's
parent rule. */
while (p)
{
if (p->action)
p->action = translate_rule_action (p);
if (p)
p = p->next;
}
p = grammar;
while (p)
{
int rule_length = 0;
@@ -472,14 +489,9 @@ packgram (void)
rules[ruleno].precsym = NULL;
rules[ruleno].location = p->location;
rules[ruleno].useful = true;
rules[ruleno].action = p->action ? translate_rule_action (p) : NULL;
rules[ruleno].action = p->action;
rules[ruleno].action_location = p->action_location;
/* If this rule contains midrules, rest assured that
grammar_midrule_action inserted the midrules into grammar before this
rule. Thus, the midrule actions have already been scanned in order to
set `used' flags for this rule's rhs, so grammar_rule_check will work
properly. */
/* Don't check the generated rule 0. It has no action, so some rhs
symbols may appear unused, but the parsing algorithm ensures that
%destructor's are invoked appropriately. */