Fatal Resolutions

Symbol conflicts that cannot be resolved result in a fatal error condition. In this case, an appropriate error message is provided indicating the symbol name together with the names of the files that provided the symbols, and no output file is generated. Although the fatal condition is sufficient to terminate the link-edit, all input file processing is first completed. In this manner all fatal resolution errors can be identified.

The most common fatal error condition exists when two relocatable objects both define symbols of the same name, and neither symbol is a weak definition:

$ cat foo.c
int bar = 1;

$ cat bar.c
bar()
{ 
        return (0);
}

$ cc -dn -r -o temp.o foo.c bar.c
ld: fatal: symbol `bar' is multiply-defined:
         (file foo.o and file bar.o);
ld: fatal: File processing errors. No output written to int.o

Here foo.c and bar.c have conflicting definitions for the symbol bar. Because the link-editor cannot determine which should dominate, it usually gives up. However, the link-editor's -zmuldefs option can be used to suppress this error condition, and allow the first symbol definition to be taken.