CompoundType.members() currently returns a list of member names;
sometimes, we actually want the type and offset. So, rename members() to
member_names(), and make members() return the type and offset, using a
newly added version of functools.partial() that caches the return value.
A couple of tricky things to handle:
- The DIE hash needs to be thread-safe. This implements a lock-free
algorithm.
- We need to make sure exceptions are only raised with the GIL held.
This adds some hacky macro magic to avoid adding a bunch of
easy-to-forget boilerplate everywhere.
- We need to make sure the main thread reraises any exceptions thrown by
the worker threads.
Most of drgn.dwarf is not performance-sensitive, and the part that is
(DwarfIndex) can use some extra tuning which is easier to do in C rather
than Cython.
The lldwarf/drgn.dwarf split wasn't working out too well, and moving all
of drgn.dwarf into lldwarf (by rewriting it into C) would be way too
much work. Instead, use Cython, which results in a parser which is just
as fast but with much cleaner code overall. It also turns out lldwarf
wasn't doing GC right, so the switch also fixed that.
Resolving parameters, variables with function scope, and global
variables should work. This is just the variable resolution, no fetching
yet, but a bunch of refactors snuck in here so committing it all now.
I wrote all of this code a few months back and am just now getting
around to committing it. The low-level DWARF parsing library is pretty
solid, although it only implements a subset of DWARF so far. The CLI and
higher-level interface are experimental.
