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bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node
From: |
Stefan Monnier |
Subject: |
bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node |
Date: |
Fri, 10 Mar 2023 13:28:20 -0500 |
User-agent: |
Gnus/5.13 (Gnus v5.13) |
>> I tried cargo-culting the cpu_gc_count stuff for the memory profiler,
>> see the patch below. However, something is amiss: this assertion in
>> profiler.el sometimes triggers:
>>
>> (maphash
>> (lambda (backtrace _count)
>> (let* ((max (1- (length backtrace)))
>> (head (aref backtrace max))
>> (best-parent nil)
>> (best-match (1+ max))
>> (parents (gethash head fun-map)))
>> (pcase-dolist (`(,i . ,parent) parents)
>> (when t ;; (<= (- max i) best-match) ;Else, it can't be better.
>> (let ((match max)
>> (imatch i))
>> (cl-assert (>= match imatch)) <<<<<<<<<<<<<<<<<<<<<<<<<<<<
>> (cl-assert (function-equal (aref backtrace max)
>> (aref parent i)))
>>
>> I cannot reliably reproduce this, and don't understand what causes the
>> assertion. Any hints?
>
> Hmm... I just took a look but can't see neither why your change would
> be more likely to trigger this error than the existing code for the
> `cpu` case, nor why this assertion should always be true.
I can imagine corner cases where this could trigger, but they all
involve funny business where we change `profiler-max-stack-depth` during
a single profiling run (I think you'd need to write ad-hoc ELisp code
for that). The only other explanation I can see is that we
somehow end up with a backtrace that includes `Automatic_GC` somewhere
not at the top (maybe this can happen with a `post-gc-hook`?).
If you manage to reproduce it, I'd be interested to know the value of
`backtrace` and `parent` when the assertion fails (and maybe just save
the `log` hash-table so we can look at it). It might be a symptom of
another bug.
And I still can't see how/why this would happen only for the `memory`
profiler and not for the `cpu` profiler, so I assume it can also happen
for the `cpu` profiler and we've just been lucky not to bump into it yet.
This said, I think the patch below should fix it for the `cpu` profiler
and a similar change should fix it for your patch (and the patch is
arguably right in the sense that without this `nil` entry, the backtrace
entry created for `Automatic_GC` is not really complete).
Stefan
diff --git a/src/profiler.c b/src/profiler.c
index 8247b2e90c6..295c47a2acd 100644
--- a/src/profiler.c
+++ b/src/profiler.c
@@ -423,7 +423,7 @@ DEFUN ("profiler-cpu-log", Fprofiler_cpu_log,
Sprofiler_cpu_log,
more for our use afterwards since we can't rely on its special
pre-allocated keys anymore. So we have to allocate a new one. */
cpu_log = profiler_cpu_running ? make_log () : Qnil;
- Fputhash (make_vector (1, QAutomatic_GC),
+ Fputhash (CALLN (Fvector, QAutomatic_GC, Qnil),
make_fixnum (cpu_gc_count),
result);
cpu_gc_count = 0;
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Eli Zaretskii, 2023/03/01
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Stefan Monnier, 2023/03/01
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Eli Zaretskii, 2023/03/01
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Stefan Monnier, 2023/03/01
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Eli Zaretskii, 2023/03/04
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Stefan Monnier, 2023/03/08
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node,
Stefan Monnier <=
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Stefan Monnier, 2023/03/10
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Eli Zaretskii, 2023/03/11
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Stefan Monnier, 2023/03/11
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Po Lu, 2023/03/10
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Stefan Monnier, 2023/03/10
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Po Lu, 2023/03/10
- bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Stefan Monnier, 2023/03/10
bug#60237: 30.0.50; tree sitter core dumps when I edebug view a node, Po Lu, 2023/03/02