Re: [RFA] Artifical dwarf2 debug info

[Andrew Cagney <ac131313@redhat.com>]

   fde = get_fde_for_addr (context->ra - 1);
 > >+
 > >+  if (fde == NULL)
 > >+    fde = guess_generic_fde (context->ra - 1);
 > >
 > >   if (fde == NULL)
 > >     return;

Just to be clear.  The above is the change that I think is wrong.

Instead of this function `guessing' the source of the FDE, the code 
needs to be re-structured so that the caller always supplies a 
pre-created FDE.

That way a dwarf2 cfi frame can call the above function with an FDE 
built from the object files debug info, while an artifical frame can 
call it with an artifically created FDE.   There is no guessing involved.

--

This is part of a long standing problem - it predates dwarf2cf by many 
years.  Instead of using recursion, people modify debug/target dependent 
frame code so that it attempts to directly handle all cases.  Cf all the 
PC_IN_CALL_DUMMY(frame->next), PC_IN_SIGTRAMP(frame->next) and other 
tests scattered through out the -tdep.c code; and the calls to 
get_next_frame() in dwarf2cfi.c.


Andrew