Reland "[FIRRTL][LowerClass] Pre-allocate namespaces before capturing refs (#7102)". #7328
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… refs (#7102)". This was originally added to avoid a use-after-free. However, it got removed as part of f4920aa. It seems this is still required, even when we process PathTrackers sequentially. I confirmed there was a use-after-free without this change, which is fixed after adding this back. Closes #7327.
dtzSiFive
approved these changes
Jul 16, 2024
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LGTM, especially if its fixes the issue found.
Doing this lazily is nice, although perhaps as we lean more on these things we're likely to need this for all modules anyway.
I'd like to root this out a bit more thoroughly (is there a move constructor missing? maybe the collection uses unique_ptr's? or just a comment?) but this looks correct and reliable way to fix this with what we have now, thanks!
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Yeah, I will say that I haven't yet dug more deeply into this, just confirmed that @uenoku's original fix here does fix the issue we see in single threaded PathTracker processing. I'll go ahead and merge this for now so main is clean. |
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Opened the linked ticket to continue the investigation: #7329 |
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This was originally added to avoid a use-after-free. However, it got removed as part of f4920aa. It seems this is still required, even when we process PathTrackers sequentially. I confirmed there was a use-after-free without this change, which is fixed after adding this back.
Closes #7327.