X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/f3bc338643cf15f345fa3a63811bd92869a42b89..3209eb1c4c5de8dd812e65da27df00c548f476fe:/src/reader.c diff --git a/src/reader.c b/src/reader.c index f18b5b82..f2e12c6b 100644 --- a/src/reader.c +++ b/src/reader.c @@ -1,7 +1,7 @@ /* Input parser for Bison Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000-2003, 2005-2007, - 2009-2012 Free Software Foundation, Inc. + 2009-2015 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -267,9 +267,9 @@ symbol_should_be_used (symbol_list const *s, bool *midrule_warning) return true; if ((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)) + && (symbol_list_n_get (s->midrule_parent_rule, + s->midrule_parent_rhs_index) + ->action_props.is_value_used))) { *midrule_warning = true; return true; @@ -321,18 +321,30 @@ grammar_rule_check (const symbol_list *r) bool midrule_warning = false; if (!l->action_props.is_value_used && symbol_should_be_used (l, &midrule_warning) - /* The default action, $$ = $1, `uses' both. */ + /* The default action, $$ = $1, 'uses' both. */ && (r->action_props.code || (n != 0 && n != 1))) { warnings warn_flag = midrule_warning ? Wmidrule_values : Wother; if (n) - complain (&r->location, warn_flag, _("unused value: $%d"), n); + complain (&l->location, warn_flag, _("unused value: $%d"), n); else - complain (&r->location, warn_flag, _("unset value: $$")); + complain (&l->location, warn_flag, _("unset value: $$")); } } } + /* Check that %empty => empty rule. */ + if (r->percent_empty_loc.start.file + && r->next && r->next->content.sym) + complain (&r->percent_empty_loc, complaint, + _("%%empty on non-empty rule")); + + /* Check that empty rule => %empty. */ + if (!(r->next && r->next->content.sym) + && !r->midrule_parent_rule + && !r->percent_empty_loc.start.file) + complain (&r->location, Wempty_rule, _("empty rule without %%empty")); + /* 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. */ @@ -430,8 +442,26 @@ grammar_current_rule_prec_set (symbol *precsym, location loc) token. */ symbol_class_set (precsym, token_sym, loc, false); if (current_rule->ruleprec) - complain (&loc, complaint, _("only one %s allowed per rule"), "%prec"); - current_rule->ruleprec = precsym; + duplicate_directive ("%prec", + current_rule->ruleprec->location, loc); + else + current_rule->ruleprec = precsym; +} + +/* Set %empty for the current rule. */ + +void +grammar_current_rule_empty_set (location loc) +{ + /* If %empty is used and -Wno-empty-rule is not, then enable + -Wempty-rule. */ + if (warning_is_unset (Wempty_rule)) + warning_argmatch ("empty-rule", 0, 0); + if (current_rule->percent_empty_loc.start.file) + duplicate_directive ("%empty", + current_rule->percent_empty_loc, loc); + else + current_rule->percent_empty_loc = loc; } /* Attach dynamic precedence DPREC to the current rule. */ @@ -446,8 +476,13 @@ grammar_current_rule_dprec_set (int dprec, location loc) complain (&loc, complaint, _("%s must be followed by positive number"), "%dprec"); else if (current_rule->dprec != 0) - complain (&loc, complaint, _("only one %s allowed per rule"), "%dprec"); - current_rule->dprec = dprec; + duplicate_directive ("%dprec", + current_rule->dprec_location, loc); + else + { + current_rule->dprec = dprec; + current_rule->dprec_location = loc; + } } /* Attach a merge function NAME with argument type TYPE to current @@ -460,9 +495,13 @@ grammar_current_rule_merge_set (uniqstr name, location loc) complain (&loc, Wother, _("%s affects only GLR parsers"), "%merge"); if (current_rule->merger != 0) - complain (&loc, complaint, _("only one %s allowed per rule"), "%merge"); - current_rule->merger = get_merge_function (name); - current_rule->merger_declaration_location = loc; + duplicate_directive ("%merge", + current_rule->merger_declaration_location, loc); + else + { + current_rule->merger = get_merge_function (name); + current_rule->merger_declaration_location = loc; + } } /* Attach SYM to the current rule. If needed, move the previous @@ -477,7 +516,7 @@ grammar_current_rule_symbol_append (symbol *sym, location loc, grammar_midrule_action (); p = grammar_symbol_append (sym, loc); if (name) - assign_named_ref(p, name); + assign_named_ref (p, name); if (sym->status == undeclared || sym->status == used) sym->status = needed; } @@ -507,7 +546,7 @@ packgram (void) { unsigned int itemno = 0; rule_number ruleno = 0; - symbol_list *p = grammar; + symbol_list *p; ritem = xnmalloc (nritems + 1, sizeof *ritem); @@ -516,9 +555,8 @@ packgram (void) rules = xnmalloc (nrules, sizeof *rules); - while (p) + for (p = grammar; p; p = p->next) { - int rule_length = 0; symbol *ruleprec = p->ruleprec; record_merge_function_type (p->merger, p->content.sym->type_name, p->merger_declaration_location); @@ -536,14 +574,14 @@ packgram (void) rules[ruleno].action_location = p->action_props.location; rules[ruleno].is_predicate = p->action_props.is_predicate; - /* If the midrule's $$ is set or its $n is used, remove the `$' from the + /* If the midrule's $$ 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)) + || (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 @@ -552,24 +590,27 @@ packgram (void) if (p != grammar) grammar_rule_check (p); - for (p = p->next; p && p->content.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) - complain (&rules[ruleno].location, fatal, _("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->content.sym->number); - /* A rule gets by default the precedence and associativity - of its last token. */ - if (p->content.sym->class == token_sym && default_prec) - rules[ruleno].prec = p->content.sym; - } + { + size_t rule_length = 0; + for (p = p->next; p->content.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) + complain (&rules[ruleno].location, fatal, _("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->content.sym->number); + /* A rule gets by default the precedence and associativity + of its last token. */ + if (p->content.sym->class == token_sym && default_prec) + rules[ruleno].prec = p->content.sym; + } + } /* If this rule has a %prec, the specified symbol's precedence replaces the default. */ @@ -583,9 +624,6 @@ packgram (void) aver (itemno < ITEM_NUMBER_MAX); ++ruleno; aver (ruleno < RULE_NUMBER_MAX); - - if (p) - p = p->next; } aver (itemno == nritems); @@ -631,7 +669,7 @@ reader (void) gram_parse (); prepare_percent_define_front_end_variables (); - if (! complaint_issued) + if (complaint_status < status_complaint) check_and_convert_grammar (); xfclose (gram_in); @@ -713,7 +751,7 @@ check_and_convert_grammar (void) /* Insert the initial rule, whose line is that of the first rule (not that of the start symbol): - accept: %start EOF. */ + $accept: %start $end. */ { symbol_list *p = symbol_list_sym_new (accept, empty_location); p->location = grammar->location; @@ -726,7 +764,8 @@ check_and_convert_grammar (void) grammar = p; } - aver (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars); + aver (nsyms <= SYMBOL_NUMBER_MAXIMUM); + aver (nsyms == ntokens + nvars); /* Assign the symbols their symbol numbers. Write #defines for the token symbols into FDEFINES if requested. */ @@ -737,11 +776,11 @@ check_and_convert_grammar (void) 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. + 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 `$' from any midrule symbol name (also in + rule. For the same reason, all the 'used' flags must be set before + checking whether to remove '$' from any midrule symbol name (also in packgram). */ { symbol_list *sym;