Question

I am trying to keep an error count in a variable called ‘mismatches’, in which i declare in the first part of the bison file.

In my bison grammar, i set a value to that variable.

Then in the 3rd part of the bison file, in the main() function i cout its value, and it’s 0.

A very modified/cut down version of my bison file:

%{
extern "C" FILE *yyin;
extern int yylineno;
extern int yynerrs;

int yylex();

// Declare 'mismatches'
int mismatches;

%}

%error-verbose


%%

expression:
          expression ADDOP term
          {
                     cout << "Parser is now here. Going to set `mismatches` to 6";
                     mismatches = 6;
          }
          | term
          ;

%%

int  main()
{         
          // Outputs 0
          cout << mismatches;

          yyparse();

          return 1;

}

What should i do so that the variable ‘mismatches’ can be used in all parts of the bison file?

Answer 1

I think you want to output the variable after you run the parser, like so

int  main()
{         
      yyparse();
      cout << mismatches;

      return 1;
}