Semantic values being stuffed up

[David Mitchell]

I am trying to allow a user to declare constants using something along 
the lines of:

FOO EQU 1

I have a rule:

const_decl: CONST EQU IMMED { add_constant($1, $3); }

My problem is that the value of $1 here is 'FOO EQU 1', and $3 is '1'. I 
have tried adapting this to:

const_decl: constant EQU IMMED { add_constant($1, $3); }

constant: CONST { $$ = $1; fprintf(stderr, "Constant = %s\n", $$); }

I get the output: 'Constant = FOO' but the function add_constant still 
gets 'FOO EQU 1' as its first parameter. This just doesn't make sense. I 
have declared CONST and constant as char*.

Any ideas?
Thanks in advance
Dave