Re: Handing typedefs in yacc generated parsers

Dibyendu Majumdar (dibyendu@mazumdar.demon.co.uk) wrote:
: The problem with this approach was that a TYPEDEF_NAME could appear
: anywhere an IDENTIFIER was expected, causing the yacc parser (grammer
: based on K&R2) to fail.


I had this problem when writing a C compiler some while ago. My
approach was to move to the Roskind grammar (and, in fact, this proved
not to be all that much effort). I initially tried adding context
sensitivity to the lexer in a half-hearted way, and I never felt
entirely happy with the results. But your algorithm looks somewhat
more thoughtful than mine...!


A useful program which may break some compilers is:


#include <stdio.h>


typedef char x;


void foo() {
    int a=sizeof(x),x,b=sizeof(x);
    x=1;
    printf("a=%d, b=%d, x=%d\n",a,b,x);
}


void main() {
    foo();
}


I forget where this originated (maybe from the Roskind support
information).


Des

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