I am working on creating a simple compiler, I need to generate a Symantec value type, I have checked that link, and I need to add this line in my parser.y file:
%define api.value.type union
to inform the bison that the tags used with the %token and %type directives are genuine types.
but I got that strange error:
parser.y: error: '%yacc' and '%define api.value.type "union"' cannot be used together
I don't understand what the "%yacc" variable and why got that error, as far as I understand, the '%define api.value.type "union"' I can use it inside the parser normally, and I can't find any information or resources about that error.
As noted on this page of the documentation, bison includes a yacc front end that runs bison -y. The -y option forces various yacc-compatibility settings as described here.
Hence, the solution is to run bison rather than yacc.