X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/6d0ef4ec2078687dc9217ae51eea397ce7443a3d..219c26ea51779faadeef63622e272601c6dd804e:/src/reader.c
diff --git a/src/reader.c b/src/reader.c
index 5084618f..19b1044b 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -1,28 +1,25 @@
/* Input parser for Bison
- Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,
- 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000-2003, 2005-2007,
+ 2009-2010 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
@@ -70,27 +67,6 @@ grammar_start_symbol_set (symbol *sym, location loc)
}
}
-
-/*---------------------------------------------------------------------.
-| 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);
-}
-
/*------------------------------------------------------------------------.
@@ -148,7 +124,7 @@ record_merge_function_type (int merger, uniqstr type, location declaration_loc)
merge_function != NULL && merger_find != merger;
merge_function = merge_function->next)
merger_find += 1;
- assert (merge_function != NULL && merger_find == merger);
+ aver (merge_function != NULL && merger_find == merger);
if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))
{
complain_at (declaration_loc,
@@ -196,7 +172,7 @@ static symbol_list *grammar_end = NULL;
static void
grammar_symbol_append (symbol *sym, location loc)
{
- symbol_list *p = symbol_list_new (sym, loc);
+ symbol_list *p = symbol_list_sym_new (sym, loc);
if (grammar_end)
grammar_end->next = p;
@@ -225,13 +201,6 @@ static symbol_list *previous_rule_end = NULL;
void
grammar_current_rule_begin (symbol *lhs, location loc)
{
- if (!start_flag)
- {
- startsymbol = lhs;
- startsymbol_location = loc;
- start_flag = true;
- }
-
/* Start a new rule and record its lhs. */
++nrules;
previous_rule_end = grammar_end;
@@ -251,16 +220,25 @@ grammar_current_rule_begin (symbol *lhs, location loc)
/*----------------------------------------------------------------------.
-| 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->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;
}
/*----------------------------------------------------------------.
@@ -278,13 +256,13 @@ grammar_rule_check (const symbol_list *r)
Don't worry about the default action if $$ is untyped, since $$'s
value can't be used. */
- if (!r->action && r->sym->type_name)
+ if (!r->action_props.code && r->content.sym->type_name)
{
- symbol *first_rhs = r->next->sym;
+ symbol *first_rhs = r->next->content.sym;
/* If $$ is being set in default way, report if any type mismatch. */
if (first_rhs)
{
- char const *lhs_type = r->sym->type_name;
+ char const *lhs_type = r->content.sym->type_name;
const char *rhs_type =
first_rhs->type_name ? first_rhs->type_name : "";
if (!UNIQSTR_EQ (lhs_type, rhs_type))
@@ -302,11 +280,11 @@ grammar_rule_check (const symbol_list *r)
{
symbol_list const *l = r;
int n = 0;
- for (; l && l->sym; l = l->next, ++n)
- if (! (l->used
+ for (; l && l->content.sym; l = l->next, ++n)
+ if (! (l->action_props.is_value_used
|| !symbol_should_be_used (l)
/* The default action, $$ = $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);
@@ -314,6 +292,15 @@ grammar_rule_check (const symbol_list *r)
warn_at (r->location, _("unset value: $$"));
}
}
+
+ /* See comments in grammar_current_rule_prec_set for how POSIX
+ mandates this complaint. It's only for identifiers, so skip
+ it for char literals and strings, which are always tokens. */
+ if (r->ruleprec
+ && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"'
+ && !r->ruleprec->declared && !r->ruleprec->prec)
+ warn_at (r->location, _("token for %%prec is not defined: %s"),
+ r->ruleprec->tag);
}
@@ -346,9 +333,9 @@ grammar_midrule_action (void)
/* Make a DUMMY nonterminal, whose location is that of the midrule
action. Create the MIDRULE. */
- location dummy_location = current_rule->action_location;
+ location dummy_location = current_rule->action_props.location;
symbol *dummy = dummy_symbol_get (dummy_location);
- symbol_list *midrule = symbol_list_new (dummy, dummy_location);
+ symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
/* Make a new rule, whose body is empty, before the current one, so
that the action just read can belong to it. */
@@ -356,12 +343,11 @@ grammar_midrule_action (void)
++nritems;
/* Attach its location and actions to that of the DUMMY. */
midrule->location = dummy_location;
- midrule->action = current_rule->action;
- midrule->action_location = dummy_location;
- current_rule->action = NULL;
- /* The action has not been translated yet, so $$ 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;
@@ -369,7 +355,7 @@ grammar_midrule_action (void)
grammar = midrule;
/* End the dummy's rule. */
- midrule->next = symbol_list_new (NULL, dummy_location);
+ midrule->next = symbol_list_sym_new (NULL, dummy_location);
midrule->next->next = current_rule;
previous_rule_end = midrule->next;
@@ -387,6 +373,17 @@ grammar_midrule_action (void)
void
grammar_current_rule_prec_set (symbol *precsym, location loc)
{
+ /* POSIX says that any identifier is a nonterminal if it does not
+ appear on the LHS of a grammar rule and is not defined by %token
+ or by one of the directives that assigns precedence to a token. We
+ ignore this here because the only kind of identifier that POSIX
+ allows to follow a %prec is a token and because assuming it's a
+ token now can produce more logical error messages. Nevertheless,
+ grammar_rule_check does obey what we believe is the real intent of
+ POSIX here: that an error be reported for any identifier that
+ appears after %prec but that is not defined separately as a
+ token. */
+ 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;
@@ -426,7 +423,7 @@ grammar_current_rule_merge_set (uniqstr name, location loc)
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);
}
@@ -436,12 +433,12 @@ grammar_current_rule_symbol_append (symbol *sym, location 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);
}
@@ -468,11 +465,11 @@ packgram (void)
{
int rule_length = 0;
symbol *ruleprec = p->ruleprec;
- record_merge_function_type (p->merger, p->sym->type_name,
+ record_merge_function_type (p->merger, p->content.sym->type_name,
p->merger_declaration_location);
rules[ruleno].user_number = ruleno;
rules[ruleno].number = ruleno;
- rules[ruleno].lhs = p->sym;
+ rules[ruleno].lhs = p->content.sym;
rules[ruleno].rhs = ritem + itemno;
rules[ruleno].prec = NULL;
rules[ruleno].dprec = p->dprec;
@@ -480,21 +477,26 @@ 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_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. */
if (p != grammar)
grammar_rule_check (p);
- for (p = p->next; p && p->sym; p = p->next)
+ for (p = p->next; p && p->content.sym; p = p->next)
{
++rule_length;
@@ -505,11 +507,12 @@ packgram (void)
/* item_number = symbol_number.
But the former needs to contain more: negative rule numbers. */
- ritem[itemno++] = symbol_number_as_item_number (p->sym->number);
+ ritem[itemno++] =
+ symbol_number_as_item_number (p->content.sym->number);
/* A rule gets by default the precedence and associativity
of its last token. */
- if (p->sym->class == token_sym && default_prec)
- rules[ruleno].prec = p->sym;
+ if (p->content.sym->class == token_sym && default_prec)
+ rules[ruleno].prec = p->content.sym;
}
/* If this rule has a %prec,
@@ -521,15 +524,15 @@ packgram (void)
}
/* An item ends by the rule number (negated). */
ritem[itemno++] = rule_number_as_item_number (ruleno);
- assert (itemno < ITEM_NUMBER_MAX);
+ aver (itemno < ITEM_NUMBER_MAX);
++ruleno;
- assert (ruleno < RULE_NUMBER_MAX);
+ aver (ruleno < RULE_NUMBER_MAX);
if (p)
p = p->next;
}
- assert (itemno == nritems);
+ aver (itemno == nritems);
if (trace_flag & trace_sets)
ritem_print (stderr);
@@ -564,10 +567,6 @@ reader (void)
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;
@@ -607,31 +606,66 @@ check_and_convert_grammar (void)
endtoken->user_token_number = 0;
}
+ /* Find the start symbol if no %start. */
+ if (!start_flag)
+ {
+ symbol_list *node;
+ for (node = grammar;
+ node != NULL && symbol_is_dummy (node->content.sym);
+ node = node->next)
+ {
+ for (node = node->next;
+ node != NULL && node->content.sym != NULL;
+ node = node->next)
+ ;
+ }
+ aver (node != NULL);
+ grammar_start_symbol_set (node->content.sym,
+ node->content.sym->location);
+ }
+
/* Insert the initial rule, whose line is that of the first rule
(not that of the start symbol):
accept: %start EOF. */
{
- symbol_list *p = symbol_list_new (accept, empty_location);
+ symbol_list *p = symbol_list_sym_new (accept, empty_location);
p->location = grammar->location;
- p->next = symbol_list_new (startsymbol, empty_location);
- p->next->next = symbol_list_new (endtoken, empty_location);
- p->next->next->next = symbol_list_new (NULL, empty_location);
+ p->next = symbol_list_sym_new (startsymbol, empty_location);
+ p->next->next = symbol_list_sym_new (endtoken, empty_location);
+ p->next->next->next = symbol_list_sym_new (NULL, empty_location);
p->next->next->next->next = grammar;
nrules += 1;
nritems += 3;
grammar = p;
}
- assert (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);
+ aver (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);
/* Assign the symbols their symbol numbers. Write #defines for the
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 ();
/* The grammar as a symbol_list is no longer needed. */
- LIST_FREE (symbol_list, grammar);
+ symbol_list_free (grammar);
}