Spurious warning "unset value: $$"

[Debashis De]

Hello,

Here is my log:

address@hidden src]$ ./bison --version
bison (GNU Bison) 3.0.4
Written by Robert Corbett and Richard Stallman.

Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
address@hidden src]$ cat ~/t.y
%start st1

%destructor { } st1

%type <int> st2
%token st3

%%

st1 : st2 { /* $$ = 0 ; */ } ;

st2 : st3 { $$ = 0 ; } ;

%%

address@hidden src]$ ./bison ~/t.y
/home/debashis/t.y:10.7-28: warning: unset value: $$ [-Wother]
 st1 : st2 { /* $$ = 0 ; */ } ;
       ^^^^^^^^^^^^^^^^^^^^^^
address@hidden src]$

Thanks and regards,
Debashis

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