Hi,

The attached patch makes an incompatible change to the JIT reader
interface to pass the target address of the symfile to the
read_debug_info, instead of eagerly copying the symfile to GDB and
passing the local address to the .so.  In many cases this allows the
target to be simpler, as in many cases it's not necessary to allocate a
symfile object at all.  In the case where you do need the memory in the
GDB address space, well the target_read() callback is there for you.

I have a patch coming that will allow JIT readers to be implemented in
Guile.  It uses the JIT reader interface, though loaded from an
extension instead of a shared library.  This patch would help extensions
to be able to do JIT unwinding, as extensions have a much richer
interface to GDB and in particular can query types and sizes from the
inferior, without having to hard-code them from the reader side.  What
you want is the target address, not the target's memory.

WDYT?