Commit Graph

9 Commits

Author SHA1 Message Date
Omar Sandoval
5200a6652c libdrgn: embed memory reader, type index, and symbol index in program 2019-05-06 14:55:34 -07:00
Omar Sandoval
bb2357bc09 libdrgn: don't require word size for type index initialization 2019-05-06 14:55:34 -07:00
Omar Sandoval
ba162ac001 libdrgn: remove endianness from type index
The type index doesn't need to know or care about endianness. Move it to
the program.
2019-05-06 14:55:34 -07:00
Omar Sandoval
a98445c277 libdrgn: make type index pluggable with callbacks
Similar to "libdrgn: make memory reader pluggable with callbacks", we
want to support custom type indexes (imagine, e.g., using drgn to parse
a binary format). For now, this disables the dwarf index tests; we'll
have a better way to test them later, so let's not bother adding more
test scaffolding.
2019-05-06 14:55:34 -07:00
Omar Sandoval
043cddf6d8 libdrgn: move member cache to type index
It makes more sense here than in struct drgn_program.
2019-05-06 14:55:34 -07:00
Omar Sandoval
3645ce78ea libdrgn: assume all pointers have same size in type index 2019-05-06 14:55:34 -07:00
Omar Sandoval
06960f591c libdrgn: look up primitive types on demand
Instead of caching all primitive types ahead of time, look them up on
demand. This is preparation for making the type index API more flexible.
2019-05-06 14:55:34 -07:00
Omar Sandoval
932b7857b5 libdrgn: expose primitive type concept to public interface
Previously known as c_type.
2019-05-06 14:55:34 -07:00
Omar Sandoval
75c3679147 Rewrite drgn core in C
The current mixed Python/C implementation works well, but it has a
couple of important limitations:

- It's too slow for some common use cases, like iterating over large
  data structures.
- It can't be reused in utilities written in other languages.

This replaces the internals with a new library written in C, libdrgn. It
includes Python bindings with mostly the same public interface as
before, with some important improvements:

- Types are now represented by a single Type class rather than the messy
  polymorphism in the Python implementation.
- Qualifiers are a bitmask instead of a set of strings.
- Bit fields are not considered a separate type.
- The lvalue/rvalue terminology is replaced with reference/value.
- Structure, union, and array values are better supported.
- Function objects are supported.
- Program distinguishes between lookups of variables, constants, and
  functions.

The C rewrite is about 6x as fast as the original Python when using the
Python bindings, and about 8x when using the C API directly.

Currently, the exposed API in C is fairly conservative. In the future,
the memory reader, type index, and object index APIs will probably be
exposed for more flexibility.
2019-04-02 14:12:07 -07:00