Memory blocks in the trace buffer are limited to 65K (to save a couple 
bytes in the length field, since most blocks are small), and a tester 
trying to collect a quarter-megabyte(!) C++ object ran into trouble with 
that.  The fix is really a target-side thing, but the trace file reader 
needs to cognizant of this detail also.  Fortunately, we can exploit 
GDB's partial xfer mechanism, and just return what we find in one block, 
expecting that GDB will re-request the remainder.

I also made the tfile target has_all_memory, and added an emulation of 
QTro behavior, which lets disassembly and the like work, but rejects 
attempts to print non-constant globals that were not collected.  
Committed to trunk.

Stan

2010-04-05  Stan Shebs  <stan@codesourcery.com>

    * tracepoint.c: Include gdbcore.h.
    (tfile_xfer_partial): Return partial results, also try reading
    from executable.
    (tfile_has_all_memory): New function.
    (init_tfile_ops): Use it.

    * gdb.trace/tfile.c: Add a variable split across two blocks, and a
    constant global.
    * gdb.trace/tfile.exp: Try to print them.