/* Input parser for Bison
Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,
- 2005, 2006 Free Software Foundation, Inc.
+ 2005, 2006, 2007 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
}
}
-
-/*---------------------------------------------------------------------.
-| There are two prologues: one before the first %union and one after. |
-| Augment the one specified by POST. |
-`---------------------------------------------------------------------*/
-
-void
-prologue_augment (const char *prologue, location loc, bool post)
-{
- struct obstack *oout =
- !post ? &pre_prologue_obstack : &post_prologue_obstack;
-
- obstack_fgrow1 (oout, "]b4_syncline(%d, [[", loc.start.line);
- /* FIXME: Protection of M4 characters missing here. See
- output.c:escaped_output. */
- MUSCLE_OBSTACK_SGROW (oout,
- quotearg_style (c_quoting_style, loc.start.file));
- obstack_sgrow (oout, "]])[\n");
- obstack_sgrow (oout, prologue);
-}
-
\f
/*------------------------------------------------------------------------.
/*----------------------------------------------------------------------.
-| A symbol should be used if it has a destructor, 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; }". |
+| A symbol should be used if either: |
+| 1. It has a destructor. |
+| 2. --warnings=midrule-values and the symbol is a mid-rule symbol |
+| (i.e., the generated LHS replacing a mid-rule action) that was |
+| assigned to or used, as in "exp: { $$ = 1; } { $$ = $1; }". |
`----------------------------------------------------------------------*/
static bool
symbol_should_be_used (symbol_list const *s)
{
- return (symbol_destructor_get (s->content.sym)
- || (s->midrule && s->midrule->used));
+ if (symbol_destructor_get (s->content.sym)->code)
+ return true;
+ if (warnings_flag & warnings_midrule_values)
+ return ((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));
+ return false;
}
/*----------------------------------------------------------------.
Don't worry about the default action if $$ is untyped, since $$'s
value can't be used. */
- if (!r->action && r->content.sym->type_name)
+ if (!r->action_props.code && r->content.sym->type_name)
{
symbol *first_rhs = r->next->content.sym;
/* If $$ is being set in default way, report if any type mismatch. */
symbol_list const *l = r;
int n = 0;
for (; l && l->content.sym; l = l->next, ++n)
- if (! (l->used
+ if (! (l->action_props.is_value_used
|| !symbol_should_be_used (l)
/* The default action, $$ = $1, `uses' both. */
- || (!r->action && (n == 0 || n == 1))))
+ || (!r->action_props.code && (n == 0 || n == 1))))
{
if (n)
warn_at (r->location, _("unused value: $%d"), n);
/* Make a DUMMY nonterminal, whose location is that of the midrule
action. Create the MIDRULE. */
- location dummy_location = current_rule->action_location;
+ location dummy_location = current_rule->action_props.location;
symbol *dummy = dummy_symbol_get (dummy_location);
symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
++nritems;
/* Attach its location and actions to that of the DUMMY. */
midrule->location = dummy_location;
- midrule->action = current_rule->action;
- midrule->action_location = dummy_location;
- current_rule->action = NULL;
- /* The action has not been translated yet, so $$ use hasn't been
- detected yet. */
- midrule->used = false;
+ code_props_rule_action_init (&midrule->action_props,
+ current_rule->action_props.code,
+ current_rule->action_props.location,
+ midrule);
+ code_props_none_init (¤t_rule->action_props);
if (previous_rule_end)
previous_rule_end->next = midrule;
void
grammar_current_rule_prec_set (symbol *precsym, location loc)
{
+ symbol_class_set (precsym, token_sym, loc, false);
if (current_rule->ruleprec)
complain_at (loc, _("only one %s allowed per rule"), "%prec");
current_rule->ruleprec = precsym;
void
grammar_current_rule_symbol_append (symbol *sym, location loc)
{
- if (current_rule->action)
+ if (current_rule->action_props.code)
grammar_midrule_action ();
grammar_symbol_append (sym, loc);
}
void
grammar_current_rule_action_append (const char *action, location loc)
{
- if (current_rule->action)
+ if (current_rule->action_props.code)
grammar_midrule_action ();
/* After all symbol declarations have been parsed, packgram invokes
- translate_rule_action. */
- current_rule->action = action;
- current_rule->action_location = loc;
+ code_props_translate_code. */
+ code_props_rule_action_init (¤t_rule->action_props, action, loc,
+ current_rule);
}
\f
rules[ruleno].precsym = NULL;
rules[ruleno].location = p->location;
rules[ruleno].useful = true;
- rules[ruleno].action = p->action ? translate_rule_action (p) : NULL;
- rules[ruleno].action_location = p->action_location;
-
- /* If this rule contains midrules, rest assured that
- grammar_midrule_action inserted the midrules into grammar before this
- rule. Thus, the midrule actions have already been scanned in order to
- set `used' flags for this rule's rhs, so grammar_rule_check will work
- properly. */
+ rules[ruleno].action = p->action_props.code;
+ rules[ruleno].action_location = p->action_props.location;
+
+ /* If the midrule's $$ 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))
+ p->content.sym->tag += 1;
+
/* 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. */
undeftoken->class = token_sym;
undeftoken->number = ntokens++;
- /* Initialize the obstacks. */
- obstack_init (&pre_prologue_obstack);
- obstack_init (&post_prologue_obstack);
-
gram_in = xfopen (grammar_file, "r");
gram__flex_debug = trace_flag & trace_scan;
token symbols into FDEFINES if requested. */
symbols_pack ();
+ /* Scan rule actions after invoking symbol_check_alias_consistency (in
+ symbols_pack above) so that token types are set correctly before the rule
+ 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.
+ 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
+ packgram). */
+ for (symbol_list *sym = grammar; sym; sym = sym->next)
+ code_props_translate_code (&sym->action_props);
+
/* Convert the grammar into the format described in gram.h. */
packgram ();
/* The grammar as a symbol_list is no longer needed. */
- LIST_FREE (symbol_list, grammar);
+ symbol_list_free (grammar);
}
projects / bison.git / blobdiff