Problem with DWARF2 debug info for DJGPP
Mark E.
snowball3@softhome.net
Sat Aug 10 14:32:00 GMT 2002
I figured out what's going on, but I have no idea what to do about.
> I'm getting error message about wrong DWARF2 abbrev when attemting to link
> program which contains reference to unresolved symbol
> > gcc -S -gdwarf-2 produces:
> .section .debug_info,""
> .long 0x61
> .word 0x2
> .long Ldebug_abbrev0
> .byte 0x4
> .uleb128 0x1
> .long Ldebug_line0
When ld is processing a section in the object file and discovers a symbol is
undefined, it prints a message that includes the file and line number. The
routines that do this use bfd_find_nearest_line() to get at this info. With
the testcase, 'foo' is discovered to be undefined and dwarf2 information has
been generated for it. However, the .debug_info section hasn't yet been
processed by the linker so it still has relocations. Since relocations aren't
section-relative in COFF, '.long Ldebug_abbrev0' doesn't evaluate to '.long
0' in the generated object file like it does in the equivalent ELF version.
I guess the difference between the two is because they represent relocations
somewhat differently (ELF uses section-relative relocations, COFF doesn't?).
Until someone can come up with a solution, just make a note that the dwarf2
warning message is a known problem.
Mark
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