Debugger: "data breakpoints": break when the command executed matches a certain regex

[singalen]

I have a huge set of makefiles. I need to find what creates a certain directory. I would like to set a breakpoint that triggers:

• when a command that matches .+mkdir.+problem_directory$ is executed.

The current breakpoints are useful when you know what file and line you want to stop at, but they cannot stop when a certain file is accessed.

[rocky]

Ok. Sounds interesting. You are up for working on it yourself?

[singalen]

I made some initial research in the code. This should be doable, but no promises. The condition should be checked somewhere around start_job_command(), and I need to call enter_debugger() - is this correct?

[rocky]

I'd stay out of src which is mostly GNU Make and work as much as possible in libdebugger

To get started I might modify info targets so that instead of printing everything it filters according to some pattern. But no promises ;-)

[singalen]

Sorry, how would it help to create a data breakpoint? To be clear, I don't want to filter existing breakpoints by condition. I want to have a pure-data breakpoint, that triggers whenever ANY command matches a given regex.

To do this, I need to:

• create a new breakpoint data structure. Unlike breakpoint_node, it needs to be disconnected from a file location, but to have a command regex;
• hook up to a code that executes every command in a target and probably in $(shell) too, after variable expansion (I wonder how this plays with .ONESHELL);
• provide an API for libdebug to either list its regex breakpoints or to match the given command to regex breakpoints;
• trigger a debugger.

Does this sound reasonable?

[rocky]

Ok - I think I see now. So yes, I think new_job in jobs.c is where you want to change.

And what you write sounds reasonable.

Still though, you would do well to change job.c a little as possible. It's already complicated and ugly enough. If you can just put inside new_job a call to a new routine inside libdebugger to make the additional check and trigger when true.