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ccompiler-constructionyacclex

getting shift/reduce errors in my grammar

This is the part of grammar for my programming language. I am getting shift/reduce conflicts while compiling.

Rule 1:    encryption_spec: key_spec 

Rule 2:   key_spec:
    key_spec key_spec_content
    | key_spec_content
    ;

Rule 3:    key_spec_content: TOK_PROTECT key_keyowner 
    |TOK_PROTECT key_keyname
    |TOK_PROTECT key_keymethod
    |TOK_PROTECT key_pub_key
    |TOK_COMMA key_keyowner 
    |TOK_COMMA key_keyname
    |TOK_COMMA key_keymethod
    |TOK_COMMA key_pub_key
    |encoding
    ;

I am getting shift/reduce conflict in Rule 1. Can you please suggest me something to modify ?

Solution

  • Your key_spec rule is malformed. Indeed you have an infinite recursion.
    You should change it for something like

    key_spec: /* Empty. */
    | key_spec key_spec_content
;

    EDIT: Remove the %empty bison extension.