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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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13
ChangeLog
View File

@@ -1,3 +1,16 @@
2006-10-20 Joel E. Denny <jdenny@ces.clemson.edu>
Warn about unset midrule $$ if the corresponding $n is used.
* src/reader.c (symbol_should_be_used): Check midrule parent rule for
$n usage.
(packgram): Before invoking grammar_rule_check on any rule, make sure
all actions have already been scanned in order to set `used' flags.
Otherwise, checking that a midrule's $$ 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.
2006-10-20 Joel E. Denny <jdenny@ces.clemson.edu>
More improvements to the documentation of the prologue alternatives:

26
src/reader.c
View File

@@ -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. */

19
tests/input.at
View File

@@ -103,8 +103,8 @@ start:
a: INT | INT { } INT { } INT { };
b: INT | /* empty */;
c: INT | INT { $]1[ } INT { } INT { };
d: INT | INT { } INT { $]1[ } INT { };
c: INT | INT { $]1[ } INT { $<integer>2 } INT { $<integer>4 };
d: INT | INT { } INT { $]1[ } INT { $<integer>2 };
e: INT | INT { } INT { } INT { $]1[ };
f: INT | INT { } INT { } INT { $]$[ = $]1[ + $]3[ + $]5[; };
g: INT | INT { $<integer>$; } INT { $<integer>$; } INT { };
@@ -122,12 +122,15 @@ input.y:11.10-32: warning: unused value: $]1[
input.y:11.10-32: warning: unused value: $]3[
input.y:11.10-32: warning: unused value: $]5[
input.y:12.9: warning: empty rule for typed nonterminal, and no action
input.y:13.10-35: warning: unset value: $]$[
input.y:13.10-35: warning: unused value: $]3[
input.y:13.10-35: warning: unused value: $]5[
input.y:14.10-35: warning: unset value: $]$[
input.y:14.10-35: warning: unused value: $]3[
input.y:14.10-35: warning: unused value: $]5[
input.y:13.14-19: warning: unset value: $$
input.y:13.25-39: warning: unset value: $$
input.y:13.10-59: warning: unset value: $]$[
input.y:13.10-59: warning: unused value: $]3[
input.y:13.10-59: warning: unused value: $]5[
input.y:14.14-16: warning: unset value: $$
input.y:14.10-47: warning: unset value: $]$[
input.y:14.10-47: warning: unused value: $]3[
input.y:14.10-47: warning: unused value: $]5[
input.y:15.10-36: warning: unset value: $]$[
input.y:15.10-36: warning: unused value: $]3[
input.y:15.10-36: warning: unused value: $]5[