Problem with virtual function pointers

[Corinna Vinschen <vinschen at redhat dot com>]

Hi,

I'm just investigating a problem which XStormy16 gets in
gdb.c++/printmethod.exp:

  print theA->virt^M
  $1 = invalid pointer to member function^M
  FAIL: gdb.c++/printmethod.exp: print virtual method.

It turned out that the error happens in xstormy16_pointer_to_address().
This function converts an address to a jump table entry into a pointer
to the actual function.  To do this, it calls a conversion routine,
which is only called if the following condition applies:


  enum type_code target = TYPE_CODE (TYPE_TARGET_TYPE (type));

  if (target == TYPE_CODE_FUNC || target == TYPE_CODE_METHOD)
    convert();

Surprisingly (at least for me) this fails for the above case.  Looking
into type, I found that type is TYPE_CODE_PTR which is correct, but
target_type is TYPE_CODE_VOID!  Sure, the above virtual method is of
type void but is that really ok?  Shouldn't that be 

  type: TYPE_CODE_PTR
  type->target_type: TYPE_CODE_METHOD
  type->target_type->target_type: TYPE_CODE_VOID

?

Does somebody know why that happens?  Is that just a bug in gdb?  Or
could that be related to incorrect debug info from gcc?

Corinna

-- 
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.
mailto:vinschen at redhat dot com