Bison advises that a variable 'expr' I use isn't declared.

The union in which the type for the expr variable is declared is... %union {/* this becomes yylval ! */ int val; /* GMP type required here. */ struct symtab *symp; } The declaration of the variable is... %type expr/* determines that expr is an int, though

Correct makefile for a bison/flex compilation

I presently have a compiler to write with Flex and Bison. I have a lex.l file, and a parse.y in which there are no conflicts. I also have a symtable.h included. I have a makefile as follows... project: parse.tab.o lex.yy.o echo