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fix warnings for useless %printer/%destructor

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The previous commit, which turns into a warning what used to be an
error:

    %printer {} foo;
    %%
    exp: '0';

has two shortcomings: the warning is way too long (foo is reported
to be useless later), and besides, it also turns into a warning much
more serious errors:

   %printer {} foo;
   %%
   exp: foo;

Reduce the amount to warnings in the first case, restore the error in
the second.

* src/symtab.h (status): Add a new inital state: undeclared.
* src/symtab.c (symbol_new): Initialize to undeclared.
(symbol_class_set): Simplify the logic of the code that neutralize
the "redeclared" warning after the "redefined" one.
(symbol_check_defined): "undeclared" is also an error.
* src/reader.c (grammar_current_rule_symbol_append): Symbols appearing
in a rule are "needed".
* src/symlist.c (symbol_list_destructor_set, symbol_list_printer_set):
An unknown symbol appearing in a %printer/%destructor is "used".
* src/reduce.c (nonterminals_reduce): Do not report as "useless" symbols
that are not used (e.g., those that for instance appeared only in a
%printer).
* tests/input.at (Undeclared symbols used for a printer or destructor):
Improve the cover the cases described above.
This commit is contained in:
Akim Demaille
2012-06-20 12:33:34 +02:00
parent 0d4b994cc2
commit 3b0b682fd6
6 changed files with 61 additions and 34 deletions
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39
src/symtab.c
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@@ -85,7 +85,7 @@ symbol_new (uniqstr tag, location loc)
res->alias = NULL;
res->class = unknown_sym;
res->status = needed;
res->status = undeclared;
if (nsyms == SYMBOL_NUMBER_MAXIMUM)
fatal (_("too many symbols in input grammar (limit is %d)"),
@@ -358,10 +358,12 @@ symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
void
symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
{
bool warned = false;
if (sym->class != unknown_sym && sym->class != class)
{
complain_at (loc, _("symbol %s redefined"), sym->tag);
sym->status = needed;
// Don't report both "redefined" and "redeclared".
warned = true;
}
if (class == nterm_sym && sym->class != nterm_sym)
@@ -373,7 +375,7 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
if (declaring)
{
if (sym->status == declared)
if (sym->status == declared && !warned)
warn_at (loc, _("symbol %s redeclared"), sym->tag);
sym->status = declared;
}
@@ -421,18 +423,25 @@ symbol_check_defined (symbol *sym)
{
if (sym->class == unknown_sym)
{
if (sym->status == needed)
complain_at
(sym->location,
_("symbol %s is used, but is not defined as a token and has no"
" rules"),
sym->tag);
else
warn_at
(sym->location,
_("symbol %s is used, but is not defined as a token and has no"
" rules"),
sym->tag);
switch (sym->status)
{
case used:
warn_at (sym->location,
_("symbol %s is used, but is not defined as a token"
" and has no rules"),
sym->tag);
break;
case undeclared:
case needed:
complain_at (sym->location,
_("symbol %s is used, but is not defined as a token"
" and has no rules"),
sym->tag);
break;
case declared:
/* If declared, then sym->class != unknown_sym. */
assert (0);
}
sym->class = nterm_sym;
sym->number = nvars++;