0.4.0

This version includes a major API overhaul, alongside a slew of new features and general improvements. While updating to 0.4.0 will require some substantial code modifications, it's well worth the effort, as 0.4.0 is the safest, leanest, and most featureful release of gdbstub yet!

Fun fact: Even after adding a bunch of new features and bug-fixes, the in-tree example_no_std has remained just as small! The example on the semver-fix-0.2.2 branch is 20251 bytes, while the example on 0.4.0 is 20246 bytes.

API Changes

• Rewrite the Target API in terms of "Inlineable Dyn Extension Traits" (IDETs)
  • By breaking up Target into smaller pieces which can be mixed-and-matched, it not only makes it easier to get up-and-running with gdbstub, but it also unlocks a lot of awesome internal optimizations:
    • Substantially reduces binary-size footprint by guaranteeing dead-code-elimination of parsing/handling unimplemented GDB protocol features.
    • Compile-time enforcement that certain groups of methods are implemented in-tandem (e.g: add_sw_breakpoint and remove_sw_breakpoint).
• Update the Target API with support for non-fatal error handling.
  • The old approach of only allowing *fatal* errors was woefully inadequate when dealing with potentially fallible operations such as reading from unauthorized memory (which GDB likes to do a bunch), or handling non-fatal std::io::Error that occur as a result of ExtendedMode operations. The new TargetResult/TargetError result is much more robust, and opens to door to supporting additional error handling extensions (such as LLDB's ASCII Errors).
• Update the Connection trait with new methods (flush - required, write_all, on_session_start)
• Lift Registers::RegId to Arch::RegId, and introduce new temporary RegIdImpl solution for avoiding breaking API changes due to new RegId implementations (see #29)
• Mark various RegId enums as #[non_exhaustive], allowing more registers to be added if need be.
• Error types are now marked as #[non_exhaustive].

New Protocol Extensions

• ExtendedMode - Allow targets to run new processes / attach to existing processes / restart execution.
  • Includes support for set disable-randomization, set environment, set startup-with-shell, and set cwd and cd.
• SectionOffsets - Get section/segment relocation offsets from the target. #30 (mchesser)
  • Uses the qOffsets packet under-the-hood.

Bugfixes

• Fix issues related to selecting the incorrect thread after hitting a breakpoint in multi-threaded targets.
• Ensure that set_nodelay is set when using a TcpStream as a Connection (via the new Connection::on_session_start API)
  • This should result in a noticeable performance improvement when debugging over TCP.

Misc

• Removed btou dependency.
• Removed all UTF-8 aware str handling code.
  • GDB uses a pure ASCII protocol, so including code to deal with UTF-8 resulted in unnecessary binary bloat.