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 will be generated. Although the fatal condition is sufficient to terminate the link-edit, all input file processing will first be 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. Since the link-editor cannot determine which should dominate, it will usually give up. However, the link-editor's -z muldefs option can be used to suppress this error condition, and allows the first symbol definition to be taken.