This page exists to help plan out soh_cah_toa's GSoC project. Unfortunately it turns out to depend heavily on parts of imcc which were substantially more broken than anyone realized. Although imcc has gotten the attention of our developers, the GSoC project's schedule shouldn't make any assumptions as to whether imcc will improve. My (cotto) plan is to rework hbdb's schedule so that it can be a maximally useful debugger by the end of GSoC within the limitations of what imcc can provide. The first step is to break the original schedule into a list of discrete features and to divide those features into three groups: those that are completed, those that depend on imcc's broken line number annotations and those that don't. From there, we can work out a new schedule that will show measurable progress and be completable while avoiding some of the more egregious landmines provided by imcc.

the original schedule (with some omissions unrelated to features) is included below as a starting point.

FEATURES:

read HLL annotations read data from debug segment code instrumentation (steal from parrot-instrument) code introspection (steal from parrot-instrument) enable/disable breakpoints breakpoints (line) breakpoints (function) watchpoints (registers) reversible debugging execute until the next annotation change backtrace bytecode disassembly debugger scripting trace open file handles (including children) dynamic memory analysis (check for uninitialized values) dynamic memory analysis (destruction-triggered watchpoints) print internal debugger state info start/continue execution single-step execution print registers help source listing

Specific Details

Create an extension that would open an interpreter and be able to run code within it one opcode at a time.

Implement a shell as a user interface. Will be able to able to interpret commands, display information about current location, etc.

This may as simple as an NQP eval loop with a global dispatch table for user commands.

Use the FileHandle PMC to make the command shell a little more friendly. We can also add command line editing, command history, and tab completion.

A basic command set would include things like:

Start and continue execution with the ability to add arguments if they're not specified on the command line.

Changing the current working directory of the program.