X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/7ecec4ddf9e1640c7133e0be0788b1d30ece20ec..4b7a4c1b1c8c18e9ad2517c117442b9b7d7e671a:/src/reader.c?ds=inline
diff --git a/src/reader.c b/src/reader.c
index 24da9b74..043fea8b 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -1,28 +1,27 @@
/* Input parser for Bison
Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,
- 2005, 2006, 2007 Free Software Foundation, Inc.
+ 2005, 2006, 2007, 2009 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
- Bison is free software; you can redistribute it and/or modify
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
- Bison is distributed in the hope that it will be useful,
+ This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with Bison; see the file COPYING. If not, write to
- the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see . */
#include
#include "system.h"
+#include
#include
#include "complain.h"
@@ -37,6 +36,7 @@
#include "scan-gram.h"
#include "scan-code.h"
+static void prepare_percent_define_front_end_variables (void);
static void check_and_convert_grammar (void);
static symbol_list *grammar = NULL;
@@ -171,7 +171,7 @@ free_merger_functions (void)
static symbol_list *grammar_end = NULL;
/* Append SYM to the grammar. */
-static void
+static symbol_list *
grammar_symbol_append (symbol *sym, location loc)
{
symbol_list *p = symbol_list_sym_new (sym, loc);
@@ -187,8 +187,27 @@ grammar_symbol_append (symbol *sym, location loc)
part of it. */
if (sym)
++nritems;
+
+ return p;
+}
+
+static void
+assign_named_ref (symbol_list *p, named_ref *name)
+{
+ symbol *sym = p->content.sym;
+
+ if (name->id == sym->tag)
+ {
+ warn_at (name->loc,
+ _("duplicated symbol name for %s ignored"),
+ quote (sym->tag));
+ named_ref_free (name);
+ }
+ else
+ p->named_ref = name;
}
+
/* The rule currently being defined, and the previous rule.
CURRENT_RULE points to the first LHS of the current rule, while
PREVIOUS_RULE_END points to the *end* of the previous rule (NULL). */
@@ -201,12 +220,19 @@ static symbol_list *previous_rule_end = NULL;
`----------------------------------------------*/
void
-grammar_current_rule_begin (symbol *lhs, location loc)
+grammar_current_rule_begin (symbol *lhs, location loc,
+ named_ref *lhs_name)
{
+ symbol_list* p;
+
/* Start a new rule and record its lhs. */
++nrules;
previous_rule_end = grammar_end;
- grammar_symbol_append (lhs, loc);
+
+ p = grammar_symbol_append (lhs, loc);
+ if (lhs_name)
+ assign_named_ref(p, lhs_name);
+
current_rule = grammar_end;
/* Mark the rule's lhs as a nonterminal if not already so. */
@@ -330,6 +356,9 @@ grammar_midrule_action (void)
symbol *dummy = dummy_symbol_get (dummy_location);
symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
+ /* Remember named_ref of previous action. */
+ named_ref *action_name = current_rule->action_props.named_ref;
+
/* Make a new rule, whose body is empty, before the current one, so
that the action just read can belong to it. */
++nrules;
@@ -339,7 +368,7 @@ grammar_midrule_action (void)
code_props_rule_action_init (&midrule->action_props,
current_rule->action_props.code,
current_rule->action_props.location,
- midrule);
+ midrule, 0);
code_props_none_init (¤t_rule->action_props);
if (previous_rule_end)
@@ -355,7 +384,8 @@ grammar_midrule_action (void)
/* Insert the dummy nonterminal replacing the midrule action into
the current rule. Bind it to its dedicated rule. */
- grammar_current_rule_symbol_append (dummy, dummy_location);
+ grammar_current_rule_symbol_append (dummy, dummy_location,
+ action_name);
grammar_end->midrule = midrule;
midrule->midrule_parent_rule = current_rule;
midrule->midrule_parent_rhs_index = symbol_list_length (current_rule->next);
@@ -404,24 +434,29 @@ grammar_current_rule_merge_set (uniqstr name, location loc)
action as a mid-rule action. */
void
-grammar_current_rule_symbol_append (symbol *sym, location loc)
+grammar_current_rule_symbol_append (symbol *sym, location loc,
+ named_ref *name)
{
+ symbol_list *p;
if (current_rule->action_props.code)
grammar_midrule_action ();
- grammar_symbol_append (sym, loc);
+ p = grammar_symbol_append (sym, loc);
+ if (name)
+ assign_named_ref(p, name);
}
/* Attach an ACTION to the current rule. */
void
-grammar_current_rule_action_append (const char *action, location loc)
+grammar_current_rule_action_append (const char *action, location loc,
+ named_ref *name)
{
if (current_rule->action_props.code)
grammar_midrule_action ();
/* After all symbol declarations have been parsed, packgram invokes
code_props_translate_code. */
code_props_rule_action_init (¤t_rule->action_props, action, loc,
- current_rule);
+ current_rule, name);
}
@@ -444,20 +479,6 @@ 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 $$ 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. */
- while (p)
- {
- code_props_translate_code (&p->action_props);
- if (p)
- p = p->next;
- }
-
- p = grammar;
while (p)
{
int rule_length = 0;
@@ -570,6 +591,7 @@ reader (void)
gram_debug = trace_flag & trace_parse;
gram_scanner_initialize ();
gram_parse ();
+ prepare_percent_define_front_end_variables ();
if (! complaint_issued)
check_and_convert_grammar ();
@@ -577,6 +599,35 @@ reader (void)
xfclose (gram_in);
}
+static void
+prepare_percent_define_front_end_variables (void)
+{
+ /* Set %define front-end variable defaults. */
+ muscle_percent_define_default ("lr.keep-unreachable-states", "false");
+ {
+ char *lr_type;
+ /* IELR would be a better default, but LALR is historically the
+ default. */
+ muscle_percent_define_default ("lr.type", "lalr");
+ lr_type = muscle_percent_define_get ("lr.type");
+ if (0 != strcmp (lr_type, "canonical-lr"))
+ muscle_percent_define_default ("lr.default-reductions", "all");
+ else
+ muscle_percent_define_default ("lr.default-reductions", "accepting");
+ free (lr_type);
+ }
+
+ /* Check %define front-end variables. */
+ {
+ static char const * const values[] = {
+ "lr.type", "lalr", "ielr", "canonical-lr", NULL,
+ "lr.default-reductions", "all", "consistent", "accepting", NULL,
+ NULL
+ };
+ muscle_percent_define_check_values (values);
+ }
+}
+
/*-------------------------------------------------------------.
| Check the grammar that has just been read, and convert it to |
@@ -590,9 +641,6 @@ check_and_convert_grammar (void)
if (nrules == 0)
fatal (_("no rules in the input grammar"));
- /* Report any undefined symbols and consider them nonterminals. */
- symbols_check_defined ();
-
/* If the user did not define her ENDTOKEN, do it now. */
if (!endtoken)
{
@@ -603,6 +651,9 @@ check_and_convert_grammar (void)
endtoken->user_token_number = 0;
}
+ /* Report any undefined symbols and consider them nonterminals. */
+ symbols_check_defined ();
+
/* Find the start symbol if no %start. */
if (!start_flag)
{
@@ -643,6 +694,23 @@ check_and_convert_grammar (void)
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). */
+ {
+ symbol_list *sym;
+ for (sym = grammar; sym; sym = sym->next)
+ code_props_translate_code (&sym->action_props);
+ }
+
/* Convert the grammar into the format described in gram.h. */
packgram ();