On 9/9/21 1:19 PM, Richard Biener wrote:
> The following removes the unused config/dbx.h file and removes the
> setting of PREFERRED_DEBUGGING_TYPE from dbxcoff.h which is
> overridden by all users (djgpp/mingw/cygwin) via either including
> config/i386/djgpp.h or config/i386/cygming.h
> 
> There are still circumstances where mingw and cygwin default to
> STABS, namely when HAVE_GAS_PE_SECREL32_RELOC is not defined and
> the target defaults to 32bit code generation.
> 
> The new style handling DBX_DEBUGGING_INFO is in line with
> dbxelf.h which does not define PREFERRED_DEBUGGING_TYPE either.
> 
> The patch also removes the PREFERRED_DEBUGGING_TYPE define from
> lynx.h which always follows elfos.h already defaulting to DWARF,
> so the comment about STABS being the default is misleading and
> outdated.  There's no listed maintainer for Lynx OS.
> 
> I have not tested this in any ways but I also have no idea how
> to meaningfully do so.
> 

Cygwin/MinGW seems to have HAVE_GAS_PE_SECREL32_RELOC set with modern 
binutils for both 32bit and 64bit, so PREFERRED_DEBUGGING_TYPE should 
nearly always be set as DWARF2_DEBUG.

Tested with binutils 2.36.50.20210330.