PR/2386 [0/2]: MinGW attach to process without an exec file

[Pedro Alves <pedro_alves at portugalmail dot pt>]

Hi all,

The following two patches fix PR/2386 -
"gdb doesn't load symbols after 'gdb --pid <pid>'".

There are two MinGW related problems here, both relate
to the fact that target_so_ops are now associated
with the gdbarch in effect.  If we're not able to find the
exec file of the attached inferior, we'll not be able to
set_current_gdbarch_from_bfd.  When we need to get at the so list
of the inferior, solib_ops will return solib_null...

1 - We currently don't set a default gdb_osabi for *-*-mingw32.
    Patch 1/2 takes care of it.  This fixes the cases where for
    some reason gdb isn't able to open a bfd to the executable.
    Having a default osabi is useful for native debuggers.  For
    multi-target builds, the default will probably not make sense
    for any other target than the native -- so we may want to
    move this default osabi somewhere else, like the target interface,
    or moving the target string matching into runtime code.

2 - win32_pid_to_exec_file (target_pid_to_exec_file), is currently
    an empty stub implementation for MinGW, as I mentioned on
    http://sourceware.org/ml/gdb/2007-10/msg00104.html.
    Patch 2/2 implements support for getting at the exec file
    of native win32 processes.  The patch tries to cover every
    version of Windows we support, and tries to work even if
    psapi.dll isn't present (it isn't part of the OS).

--
Pedro Alves