Re: IEEE 695 symbol support for GDB/BFD

[Elena Zannoni <ezannoni@redhat.com>]

Chris Lewkowski writes:
 > Hi,
 > 
 > I have been trying to use GDB with IEEE 695 symbol
 > object file for 
 > debugging a m68k remote board.  I configured GDB with
 > a target of 
 > m68k-motorola-ieee and that built fine.  When I run
 > GDB and load an IEEE 695 
 > file I get the following error:
 > 
 > I'm sorry, Dave, I can't do that.  Symbol format
 > 'ieee' unknown.
 > 
 > I tracked this down to the function find_sym_fns() in
 > file symfile.c.  
 > After doing some more investigation I believe that
 > GDB/BFD does not 
 > have any methods for reading these types of symbol
 > files, although it does 
 > recognise the format.  I believe that the file
 > ieeeread.c (and 
 > functionality of course) will need to be created for
 > GDB as well as supporting 
 > read functions in the BFD library.  I am considering
 > creating this 
 > functionality but have a few questions first:
 > 
 > 1) Has anyone attempted this before?
 > 

I see that this was developed for the HP emulator, and the debugger
support remained proprietary, so no, there never was any such reader
in gdb. Seems like people use m68k-coff and then translate the files
to ieee-695 for use of the emulator.
m68k-coff-objcopy -O ieee --debugging <file> <file.x> does this.

 > 2) Does what I have described above seem like the
 > correct path to take 
 > to support this object/executable file format?  Can
 > someone give me 
 > some pointers on the best way to add this
 > functionality?
 > 

There are a number of other readers in gdb, you could look at
elfread.c, coffread.c, for instance. I would avoid looking at *read.c
files that haven't been changed recently (look at the ChangeLogs to
see this).

 > 3) Does anyone have any additional (to the standard
 > gdb docs) relevant 
 > information about the functionality of GDB's symbol
 > interpreting 
 > engine? and what steps should be taken to do this?
 > 

Sigh, no. All we have is the source code....

 > I have used the binutils program objdump and that has
 > the capability to 
 > read the IEEE 695 symbol files.  So hopefully I can
 > re-use a lot of the 
 > code from there.
 > 
 > Any help would be greatly appreciated,
 > 

Just send questions to this list, and if you want to contribute your
work, make sure you have a copyright assignment with the FSF in place.

Elena


 > Thanks,
 > 
 > Chris
 > 
 > 
 > 
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