[wasm][debugger] Fixing step over in an async method

[thaystg]

We don't have ctx available on wasm, but we don't need it to calculate the frames, the ifdef on debugger-engine.h fix the #42424.

[ghost]

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[lewing]

The context is unused in the wasm case so this looks fine. I'll double check the tests then approve.

[radical]

Why was this causing the issue with the test? Why did it specifically break the async test?

[thaystg]

Because once it doesn't execute ss_calculate_framecount because ss_args->ctx == NULL, nframes variable would be 0, and wouldn't enter in this if: if (asyncMethod && asyncMethod->num_awaits && nframes && rt_callbacks.ensure_jit (frames [0])) { and wouldn't call ss_bp_add_one

[radical]

Okay. nframes ==0 would also cause the loop starting line 1341 to get skipped, IIUC. Is there any case where that loop will get incorrectly skipped?catch`(not the last one, IIUC) in an async method? Or catch in non-async methods?

Just trying to understand with silly/naive questions 😬

[thaystg]

I think this loop would be skipped wrongly without the fix. Now the value of nframes and frames variables will be correct for both loops, line 1341 and line 1358.

[lewing]

I'm seeing some failures on the locally. @thaystg can you verify?

[lewing]

Looks like the issue is that #42486 fails to handle null strings in on of the versions of
js_string_to_mono_string. I'll open a separate pr for it because that change is only on master.

[lewing]

debugger test regressions fixed in #42658

[lewing]

@steveisok still getting cancellations we can't clear

[thaystg]

/backport to release/5.0-rc2

[github-actions]

Started backporting to release/5.0-rc2: https://github.com/dotnet/runtime/actions/runs/271123075

[github-actions]

@thaystg backporting to release/5.0-rc2 failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: Fixing step over in an async method.
error: sha1 information is lacking or useless (src/mono/mono/mini/debugger-engine.c).
error: could not build fake ancestor
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Fixing step over in an async method.
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!