Linker Error
 

I get the following error whenever i try to compile FRCcode with any variables declared in user_routines.h (in this case, "int bob;"):

MPLINK 3.40, Linker
Copyright (c) 2003 Microchip Technology Inc.
Error - symbol 'bob' has multiple definitions.
Errors : 1


I'm positive i don't have multiple definitions. It appears that user_routines.h is being included several times. i understand repeated #defines would be protected by the


but how do i protect real code (not #define's) from being repeatedly inserted?

The program compiles fine with the variables in user_routines.c, i'd just prefer these global constants to be in the header for convenience.

Re: Linker Error
 

The problem is that you are decalring bob in the header. It needs to be declared in the user_routines.c file and externed in the user_routines.h file.

So in user_routines.c it would look like:
int bob;
In user_routines.h it would be:
extern int bob;

What's happening is that each file that includes user_routines.h is creating a new copy of bob rather than just getting a reference to it.

Some compilers/linkers let you decare in the header file but in general it is not supported.

Re: Linker Error
 

Ah, right, i forgot about using extern when its in a different file. So the extern modifier tells the compiler to ignore multiple declarations?

Re: Linker Error
 

No, extern tells the compiler that it is declared in another file, your just using it.

char foo = 0;
...
extern char foo;

Re: Linker Error
 

This sounds exactly like a problem I had.
It happened to me when I was trying to define variables in the .h files
You can either use extern, or just put them in the .c files (thats what I ended up doing)