before this change, the innermost frame was all the way at the top,
which means that in very nested code you'd have to scroll though
dozens or hundreds of frames before even seeing where you are, because
the last lines (which are immediately visible when the command returns)
would be the nix code's entry point and other outer frames instead,
which is rarely relevant.
this CL reverses this order, so that the innermost frames are the last
ones printed, and thus are immediately visible. (note that this is
already how errors are printed by nix in other contexts anyway, the
debugger's :bt is the only thing that prints the trace in "forward"
order.)
because `DebugState.traces()` use the homegrown `libutil::Generator`
instead of an stdlib container, we have to do that reversing ourselves,
in this case by just storing every element in an `std::list` (in reverse
order) and then traversing it. this is feels kinda dirty, but i don't
know any other way, and it's not exactly performance-critical.
Change-Id: I9f23e40e57f72a251d65a335b3bba3c3f77b935d
it seems like the repl_characterization tests have not been actually
running correctly for a while, since tests from more than 2 years ago
that should have failed have been in the test suite and OK'd thus far.
the reason why some tests passed when they shouldn't have is because
the AST nodes used by the characterization parser didn't have a correct
comparison operator, so the tests would only fail when one of the output
line was of the wrong *kind*, but not if it had the wrong *value*. this
was fixed by simply adding a default comparator to the TextNode type as
well as every derived class.
i've taken the occasion to fix the tests that were failing now that we
are actually being strict about them. most of these are pretty boring
changes like indentation, but if possible i'd like to get an explicit
ACK from at least one or two people on the core team that these changes
are okay.
for reference, here is the zulip thread that lead to this CL:
https://zulip.lix.systems/#narrow/channel/8-Testing-.2F-functional2/topic/.E2.9C.94.20repl-characterization.20tests.20not.20failing/near/10276
ps: i had to turn clang-format off around the macro for text node
declarations because it re-formatted the entire macro, causing a lot
of noising and producing uglier code; if this isn't okay or if there's
a better alternative, please let me know!
Change-Id: I1d6d92eb3e9cb705ecfeccd7b9294d6cfd7fe25b
See [lix-project/lix#1156], but basically currently the `:st <n>`
debugger command doesn't allow any negative indices, and putting a plus
sign in front of the arg doesn't change anything; thus, we can exploit
that "design space" to allow users to move between different stack
frames easily, by simply prepending their arg with a +/- sign.
The actual behavior is little more nuanced when you account for errors:
as suggested by @pennae (thanks! :), when the user inputs an offset that
would result in an invalid frame index, the debugger instead clamps it
to the closest bound (i.e. 0 for negative offsets, $maxFrame for
positive ones) and just prints a warning.
Fixes#1156
[lix-project/lix#1156]: https://git.lix.systems/lix-project/lix/issues/1156
Change-Id: I02a0cdb6aaebbdb0515308880a3bf9c0d2fcd25e
It's 2026 and the command handler was entirely manual!
We introduce a basic command handler framework for the REPL that handles
all the previous (implicit) features reasonably well.
This also builds up the infrastructure for nicer features.
Most important feature is that now we can let external plugins adds
commands to the REPL.
There's slight REPL changes:
- errors for debugger commands are more explicit.
- short-hand have a long-hand version.
- help shows command sorted by std::map natural key sorting (based on aliases)
while keeping the special syntaxes for the REPL language at the top.
- sections were introduced for Flakes commands.
- :st was merged into one command with an optional argument marker.
Change-Id: Ibd24f994491bf5d45d4b218fd84c0944ae5050fd
Signed-off-by: Raito Bezarius <raito@lix.systems>
this also fixes a debugger bug where leaving the debugger does not clean
up old debugger state completely. in such cases the fake frame withFrame
created was left behind after the corresponding caller frame was unwound
Change-Id: I45adcd116276b03b2f87076518c9eae6fe844e06
checking whether a repl hook is set does not tell whether it's running,
which in turn means we will enter a debug repl even when not debugging.
this is not very useful when we have no debug frames to inspect at all,
as commonly happens when starting a new repl with --debugger specified.
Change-Id: I7065dc4ec29743bdd53ed99c29d6592e2ceea89c
blokyk