/* Input parser for Bison
Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,
- 2005 Free Software Foundation, Inc.
+ 2005, 2006 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
#include <config.h>
#include "system.h"
+#include <assert.h>
#include <quotearg.h>
#include "getargs.h"
#include "gram.h"
#include "muscle_tab.h"
-#include "output.h"
#include "reader.h"
#include "symlist.h"
#include "symtab.h"
+#include "scan-gram.h"
+#include "scan-code.h"
-static void grammar_midrule_action (void);
-static void grammar_symbol_append (symbol *sym, location loc);
+static void check_and_convert_grammar (void);
static symbol_list *grammar = NULL;
static bool start_flag = false;
}
-/*----------------------------------------------------------------.
-| There are two prologues: one before %union, one after. Augment |
-| the current one. |
-`----------------------------------------------------------------*/
+/*---------------------------------------------------------------------.
+| 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)
+prologue_augment (const char *prologue, location loc, bool post)
{
struct obstack *oout =
- !typed ? &pre_prologue_obstack : &post_prologue_obstack;
+ !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");
\f
-/*-------------------------------------------------------------------.
-| Return the merger index for a merging function named NAME, whose |
-| arguments have type TYPE. Records the function, if new, in |
-| MERGER_LIST. |
-`-------------------------------------------------------------------*/
+/*------------------------------------------------------------------------.
+| Return the merger index for a merging function named NAME. Records the |
+| function, if new, in MERGER_LIST. |
+`------------------------------------------------------------------------*/
static int
-get_merge_function (uniqstr name, uniqstr type, location loc)
+get_merge_function (uniqstr name)
{
merger_list *syms;
merger_list head;
if (! glr_parser)
return 0;
- if (type == NULL)
- type = uniqstr_new ("");
-
head.next = merge_functions;
for (syms = &head, n = 1; syms->next; syms = syms->next, n += 1)
if (UNIQSTR_EQ (name, syms->next->name))
{
syms->next = xmalloc (sizeof syms->next[0]);
syms->next->name = uniqstr_new (name);
- syms->next->type = uniqstr_new (type);
+ /* After all symbol type declarations have been parsed, packgram invokes
+ record_merge_function_type to set the type. */
+ syms->next->type = NULL;
syms->next->next = NULL;
merge_functions = head.next;
}
- else if (!UNIQSTR_EQ (type, syms->next->type))
- warn_at (loc, _("result type clash on merge function %s: <%s> != <%s>"),
- name, type, syms->next->type);
return n;
}
+/*-------------------------------------------------------------------------.
+| For the existing merging function with index MERGER, record the result |
+| type as TYPE as required by the lhs of the rule whose %merge declaration |
+| is at DECLARATION_LOC. |
+`-------------------------------------------------------------------------*/
+
+static void
+record_merge_function_type (int merger, uniqstr type, location declaration_loc)
+{
+ int merger_find;
+ merger_list *merge_function;
+
+ if (merger <= 0)
+ return;
+
+ if (type == NULL)
+ type = uniqstr_new ("");
+
+ merger_find = 1;
+ for (merge_function = merge_functions;
+ merge_function != NULL && merger_find != merger;
+ merge_function = merge_function->next)
+ merger_find += 1;
+ assert (merge_function != NULL && merger_find == merger);
+ if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))
+ {
+ warn_at (declaration_loc,
+ _("result type clash on merge function `%s': <%s> != <%s>"),
+ merge_function->name, type, merge_function->type);
+ warn_at (merge_function->type_declaration_location,
+ _("previous declaration"));
+ }
+ merge_function->type = uniqstr_new (type);
+ merge_function->type_declaration_location = declaration_loc;
+}
+
/*--------------------------------------.
| Free all merge-function definitions. |
`--------------------------------------*/
grammar_end = p;
- /* SYM = 0 stands for an end of rule, it is not an actual
+ /* A null SYM stands for an end of rule; it is not an actual
part of it. */
if (sym)
++nritems;
/* 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). */
-symbol_list *current_rule = NULL;
+static symbol_list *current_rule = NULL;
static symbol_list *previous_rule_end = NULL;
}
+/*----------------------------------------------------------------------.
+| 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; }". |
+`----------------------------------------------------------------------*/
+
+static bool
+symbol_should_be_used (symbol_list const *s)
+{
+ return (s->sym->destructor
+ || (s->midrule && s->midrule->used));
+}
+
/*----------------------------------------------------------------.
| Check that the rule R is properly defined. For instance, there |
| should be no type clash on the default action. |
warn_at (r->location,
_("empty rule for typed nonterminal, and no action"));
}
-
- /* Check that typed symbol values are used. */
+
+ /* Check that symbol values that should be used are in fact used. */
{
- symbol_list *l = r;
+ symbol_list const *l = r;
int n = 0;
for (; l && l->sym; l = l->next, ++n)
if (! (l->used
- || !l->sym->type_name
+ || !symbol_should_be_used (l)
/* The default action, $$ = $1, `uses' both. */
- || !r->action && (n == 0 || n == 1)))
- if (n)
- warn_at (r->location, _("unused value: $%d"), n);
- else
- warn_at (r->location, _("unset value: $$"));
+ || (!r->action && (n == 0 || n == 1))))
+ {
+ if (n)
+ warn_at (r->location, _("unused value: $%d"), n);
+ else
+ warn_at (r->location, _("unset value: $$"));
+ }
}
}
/* Put an empty link in the list to mark the end of this rule */
grammar_symbol_append (NULL, grammar_end->location);
current_rule->location = loc;
- grammar_rule_check (current_rule);
}
| rule. |
`-------------------------------------------------------------------*/
-static void
+void
grammar_midrule_action (void)
{
/* Since the action was written out with this rule's number, we must
midrule->action = current_rule->action;
midrule->action_location = dummy_location;
current_rule->action = NULL;
+ /* The action has not been translated yet, so $$ use hasn't been
+ detected yet. */
+ midrule->used = false;
if (previous_rule_end)
previous_rule_end->next = midrule;
grammar = midrule;
/* End the dummy's rule. */
- previous_rule_end = symbol_list_new (NULL, dummy_location);
- previous_rule_end->next = current_rule;
+ midrule->next = symbol_list_new (NULL, dummy_location);
+ midrule->next->next = current_rule;
- midrule->next = previous_rule_end;
+ previous_rule_end = midrule->next;
/* Insert the dummy nonterminal replacing the midrule action into
- the current rule. */
+ the current rule. Bind it to its dedicated rule. */
grammar_current_rule_symbol_append (dummy, dummy_location);
+ grammar_end->midrule = midrule;
+ midrule->midrule_parent_rule = current_rule;
+ midrule->midrule_parent_rhs_index = symbol_list_length (current_rule->next);
}
/* Set the precedence symbol of the current rule to PRECSYM. */
warn_at (loc, _("%s affects only GLR parsers"), "%merge");
if (current_rule->merger != 0)
complain_at (loc, _("only one %s allowed per rule"), "%merge");
- current_rule->merger =
- get_merge_function (name, current_rule->sym->type_name, loc);
+ current_rule->merger = get_merge_function (name);
+ current_rule->merger_declaration_location = loc;
}
/* Attach SYM to the current rule. If needed, move the previous
grammar_symbol_append (sym, loc);
}
-/* Attach an ACTION to the current rule. If needed, move the previous
- action as a mid-rule action. */
+/* Attach an ACTION to the current rule. */
void
grammar_current_rule_action_append (const char *action, location loc)
{
if (current_rule->action)
grammar_midrule_action ();
+ /* After all symbol declarations have been parsed, packgram invokes
+ translate_rule_action. */
current_rule->action = action;
current_rule->action_location = loc;
}
rule_number ruleno = 0;
symbol_list *p = grammar;
- ritem = xnmalloc (nritems, sizeof *ritem);
+ ritem = xnmalloc (nritems + 1, sizeof *ritem);
+
+ /* This sentinel is used by build_relations in gram.c. */
+ *ritem++ = 0;
+
rules = xnmalloc (nrules, sizeof *rules);
while (p)
{
+ int rule_length = 0;
symbol *ruleprec = p->ruleprec;
+ record_merge_function_type (p->merger, p->sym->type_name,
+ p->merger_declaration_location);
rules[ruleno].user_number = ruleno;
rules[ruleno].number = ruleno;
rules[ruleno].lhs = p->sym;
rules[ruleno].precsym = NULL;
rules[ruleno].location = p->location;
rules[ruleno].useful = true;
- rules[ruleno].action = p->action;
+ rules[ruleno].action = p->action ? translate_rule_action (p) : NULL;
rules[ruleno].action_location = p->action_location;
- p = p->next;
- while (p && p->sym)
+ /* 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. */
+ grammar_rule_check (p);
+
+ for (p = p->next; p && p->sym; p = p->next)
{
+ ++rule_length;
+
+ /* Don't allow rule_length == INT_MAX, since that might
+ cause confusion with strtol if INT_MAX == LONG_MAX. */
+ if (rule_length == INT_MAX)
+ fatal_at (rules[ruleno].location, _("rule is too long"));
+
/* item_number = symbol_number.
But the former needs to contain more: negative rule numbers. */
ritem[itemno++] = symbol_number_as_item_number (p->sym->number);
/* A rule gets by default the precedence and associativity
- of the last token in it. */
+ of its last token. */
if (p->sym->class == token_sym && default_prec)
rules[ruleno].prec = p->sym;
- if (p)
- p = p->next;
}
/* If this rule has a %prec,
rules[ruleno].precsym = ruleprec;
rules[ruleno].prec = ruleprec;
}
+ /* An item ends by the rule number (negated). */
ritem[itemno++] = rule_number_as_item_number (ruleno);
+ assert (itemno < ITEM_NUMBER_MAX);
++ruleno;
+ assert (ruleno < RULE_NUMBER_MAX);
if (p)
p = p->next;
}
- if (itemno != nritems)
- abort ();
+ assert (itemno == nritems);
if (trace_flag & trace_sets)
ritem_print (stderr);
gram__flex_debug = trace_flag & trace_scan;
gram_debug = trace_flag & trace_parse;
- scanner_initialize ();
+ gram_scanner_initialize ();
gram_parse ();
- /* If something went wrong during the parsing, don't try to
- continue. */
- if (complaint_issued)
- return;
+ if (! complaint_issued)
+ check_and_convert_grammar ();
+
+ xfclose (gram_in);
+}
+
- /* Grammar has been read. Do some checking */
+/*-------------------------------------------------------------.
+| Check the grammar that has just been read, and convert it to |
+| internal form. |
+`-------------------------------------------------------------*/
+
+static void
+check_and_convert_grammar (void)
+{
+ /* Grammar has been read. Do some checking. */
if (nrules == 0)
fatal (_("no rules in the input grammar"));
endtoken->user_token_number = 0;
}
- /* Insert the initial rule, which line is that of the first rule
+ /* Insert the initial rule, whose line is that of the first rule
(not that of the start symbol):
accept: %start EOF. */
grammar = p;
}
- if (! (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars))
- abort ();
-
- xfclose (gram_in);
+ assert (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars);
/* Assign the symbols their symbol numbers. Write #defines for the
token symbols into FDEFINES if requested. */
projects / bison.git / blobdiff