Using yacc parser in C files

Millenniumman · 09-27-2006, 10:49 PM

I have made a yacc/lex parser. It becomes "y.tab.c" and "y.tab.h" files and then compiles to an executable. How do I best access the parser from within a C++ file in the same project? I have tried including "y.tab.h", but none of the functions from "y.tab.c" can be found. Is there anywhere with a good guide for this? I understand how to make yacc and lex grammar files, but not how to access them from C++ progrmas.

soggycornflake · 09-28-2006, 03:40 PM

Have you wrapped the header with an extern "C"...?

My (admittedly limited) understanding of C++ is that it mangles all function names, even those that are not overloaded. So you need to explicitly tell it that the code uses C linkage (non-mangled). I.e. put a

Code:

#ifdef __cplusplus
extern "C" {
#endif

at the top of the header, and a corresponding

Code:

#ifdef __cplusplus
}
#endif

at the bottom.

Of course, you'll want to put this in the .y file really, but I'm not familiar with yacc syntax, can you specify code that goes in the header? If not, just write a script that puts it in after running yacc.

Quigi · 09-28-2006, 04:38 PM

If memory serves, you can leave the yacc part alone, and include from C++ like this,

Code:

extern "C" {
#include "y.tab.h"
}

This reduces preprocessor macros and, IMO, is a bit cleaner.