X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/03c07b039448552b5ac6c51076b88c2f15b0307f..4b7a4c1b1c8c18e9ad2517c117442b9b7d7e671a:/src/reader.c diff --git a/src/reader.c b/src/reader.c index 68e8b44e..043fea8b 100644 --- a/src/reader.c +++ b/src/reader.c @@ -21,6 +21,7 @@ #include #include "system.h" +#include #include #include "complain.h" @@ -35,6 +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; @@ -169,7 +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); @@ -185,8 +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). */ @@ -199,12 +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. */ @@ -328,6 +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; @@ -337,7 +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) @@ -353,7 +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); @@ -402,24 +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); } @@ -554,22 +591,41 @@ 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 (); - muscle_percent_define_default ("lr.default_rules", "all"); + xfclose (gram_in); +} - /* Check front-end %define variable values. */ +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.default_rules", "all", "consistent", "accepting", NULL, + "lr.type", "lalr", "ielr", "canonical-lr", NULL, + "lr.default-reductions", "all", "consistent", "accepting", NULL, NULL }; muscle_percent_define_check_values (values); } - - if (! complaint_issued) - check_and_convert_grammar (); - - xfclose (gram_in); } @@ -585,9 +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) { @@ -598,6 +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) {