- copy_guard(crule, rulelength);
- t = lex();
- }
- else if (t == LEFT_CURLY)
- {
- /* This case never occurs -wjh */
- if (actionflag)
- warn(_("two actions at end of one rule"));
- copy_action(crule, rulelength);
- actionflag = 1;
- xactions++; /* -wjh */
- t = lex();
- }
- /* If $$ is being set in default way, warn if any type
- mismatch. */
- else if (!xactions
- && first_rhs
- && lhs->type_name != first_rhs->type_name)
- {
- if (lhs->type_name == 0
- || first_rhs->type_name == 0
- || strcmp(lhs->type_name,first_rhs->type_name))
- warnss(_("type clash (`%s' `%s') on default action"),
- lhs->type_name ? lhs->type_name : "",
- first_rhs->type_name ? first_rhs->type_name : "");
- }
- /* Warn if there is no default for $$ but we need one. */
- else if (!xactions && !first_rhs && lhs->type_name != 0)
- warn(_("empty rule for typed nonterminal, and no action"));
- if (t == SEMICOLON)
- t = lex();
- }
-#if 0
- /* these things can appear as alternatives to rules. */
-/* NO, they cannot.
- a) none of the documentation allows them
- b) most of them scan forward until finding a next %
- thus they may swallow lots of intervening rules
-*/
- else if (t == TOKEN)
- {
- parse_token_decl(STOKEN, SNTERM);
- t = lex();
- }
- else if (t == NTERM)
- {
- parse_token_decl(SNTERM, STOKEN);
- t = lex();
- }
- else if (t == TYPE)
- {
- t = get_type();
- }
- else if (t == UNION)
- {
- parse_union_decl();
- t = lex();
- }
- else if (t == EXPECT)
- {
- parse_expect_decl();
- t = lex();
- }
- else if (t == START)
- {
- parse_start_decl();
- t = lex();
- }
-#endif
+ /* mark the rule's lhs as a nonterminal if not already so. */
+
+ if (lhs->class == unknown_sym)
+ {
+ lhs->class = nterm_sym;
+ lhs->value = nvars;
+ nvars++;
+ }
+ else if (lhs->class == token_sym)
+ complain (_("rule given for %s, which is a token"), lhs->tag);
+
+ /* read the rhs of the rule. */
+
+ for (;;)
+ {
+ t = lex ();
+ if (t == tok_prec)
+ {
+ t = lex ();
+ crule->ruleprec = symval;
+ t = lex ();
+ }
+
+ if (!(t == tok_identifier || t == tok_left_curly))
+ break;
+
+ /* If next token is an identifier, see if a colon follows it.
+ If one does, exit this rule now. */
+ if (t == tok_identifier)
+ {
+ bucket *ssave;
+ token_t t1;
+
+ ssave = symval;
+ t1 = lex ();
+ unlex (t1);
+ symval = ssave;
+ if (t1 == tok_colon)
+ break;
+
+ if (!first_rhs) /* JF */
+ first_rhs = symval;
+ /* Not followed by colon =>
+ process as part of this rule's rhs. */
+ }
+
+ /* If we just passed an action, that action was in the middle
+ of a rule, so make a dummy rule to reduce it to a
+ non-terminal. */
+ if (action_flag)
+ {
+ /* Since the action was written out with this rule's
+ number, we must give the new rule this number by
+ inserting the new rule before it. */
+
+ /* Make a dummy nonterminal, a gensym. */
+ bucket *sdummy = gensym ();
+
+ /* Make a new rule, whose body is empty, before the
+ current one, so that the action just read can
+ belong to it. */
+ nrules++;
+ nitems++;
+ p = symbol_list_new (sdummy);
+ /* Attach its lineno to that of the host rule. */
+ p->line = crule->line;
+ if (crule1)
+ crule1->next = p;
+ else
+ grammar = p;
+ /* End of the rule. */
+ crule1 = symbol_list_new (NULL);
+ crule1->next = crule;
+
+ p->next = crule1;
+
+ /* Insert the dummy generated by that rule into this
+ rule. */
+ nitems++;
+ p = symbol_list_new (sdummy);
+ p1->next = p;
+ p1 = p;
+
+ action_flag = 0;
+ }
+
+ if (t == tok_identifier)
+ {
+ nitems++;
+ p = symbol_list_new (symval);
+ p1->next = p;
+ p1 = p;
+ }
+ else /* handle an action. */
+ {
+ copy_action (crule, rulelength);
+ action_flag = 1;
+ xactions++; /* JF */
+ }
+ rulelength++;
+ } /* end of read rhs of rule */
+
+ /* Put an empty link in the list to mark the end of this rule */
+ p = symbol_list_new (NULL);
+ p1->next = p;
+ p1 = p;
+
+ if (t == tok_prec)
+ {
+ complain (_("two @prec's in a row"));
+ t = lex ();
+ crule->ruleprec = symval;
+ t = lex ();
+ }
+ if (t == tok_guard)
+ {
+ if (!semantic_parser)
+ complain (_("%%guard present but %%semantic_parser not specified"));
+
+ copy_guard (crule, rulelength);
+ t = lex ();
+ }
+ else if (t == tok_left_curly)
+ {
+ /* This case never occurs -wjh */
+ if (action_flag)
+ complain (_("two actions at end of one rule"));
+ copy_action (crule, rulelength);
+ action_flag = 1;
+ xactions++; /* -wjh */
+ t = lex ();
+ }
+ /* If $$ is being set in default way, report if any type
+ mismatch. */
+ else if (!xactions
+ && first_rhs && lhs->type_name != first_rhs->type_name)
+ {
+ if (lhs->type_name == 0
+ || first_rhs->type_name == 0
+ || strcmp (lhs->type_name, first_rhs->type_name))
+ complain (_("type clash (`%s' `%s') on default action"),
+ lhs->type_name ? lhs->type_name : "",
+ first_rhs->type_name ? first_rhs->type_name : "");
+ }
+ /* Warn if there is no default for $$ but we need one. */
+ else if (!xactions && !first_rhs && lhs->type_name != 0)
+ complain (_("empty rule for typed nonterminal, and no action"));
+ if (t == tok_semicolon)
+ t = lex ();
+ }
+ else
+ {
+ complain (_("invalid input: %s"), quote (token_buffer));
+ t = lex ();
+ }
projects / bison.git / blobdiff