When is

Question

When is %destructor invoked in BISON? I have the following bison code:

%union{
    char * sval; 
    Variable * vval; 
} 

%token VARIABLE 
%token L         


        

Answer 1

I figured out, that I should free() it after I perform the action, so for example

...
| String CONCAT String { $$ = concat($1,$3); free($1); free($3); }
...

That did the trick for me.