+| "%code" braceless { prologue_augment ($2, @2, true); }
+| "%code-top" braceless { prologue_augment ($2, @2, false); }
+| "%provides" braceless { muscle_code_grow ("provides", $2, @2); }
+| "%requires" braceless { muscle_code_grow ("requires", $2, @2); }
+;
+
+
+/*----------*
+ | %union. |
+ *----------*/
+
+%token PERCENT_UNION "%union";
+
+union_name:
+ /* Nothing. */ {}
+| ID { muscle_code_grow ("union_name", $1, @1); }
+;
+
+grammar_declaration:
+ "%union" union_name "{...}"
+ {
+ char const *body = $3;
+
+ /* Concatenate the %union bodies. If this is the first %union, make sure
+ the synchronization line appears after the opening '{' so as not to
+ confuse Doxygen. Otherwise, turn the previous %union's trailing '}'
+ into '\n', and omit the new %union's leading '{'. */
+ if (!union_seen)
+ {
+ muscle_grow ("stype", "{", "");
+ }
+ else
+ {
+ char *code = muscle_find ("stype");
+ code[strlen (code) - 1] = '\n';
+ }
+ body++;
+
+ union_seen = true;
+ muscle_code_grow ("stype", body, @3);
+ }