Control Flow Visualizer (CFViz): an rr / gdb plugin

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25 pointsingve3 comments

> While designed with rr in mind, CFViz also works with vanilla gdb, with the limitation that it will only visualize the rest of the function’s execution from the point where it was invoked (since, without rr, it cannot go backwards to the function’s starting point).

I'm not sure this is correct. If you have a new enough version of GDB, I think you can reverse-step and reverse-next.

You're right, gdb has had some reverse debugging support since version 7.0 released in 2009.

https://www.gnu.org/software/gdb/news/reversible.html

GDB's built-in record and replay target is too slow to be very useful. It laboriously breaks on every instruction, decodes it, and records its effects; rr is much, much smarter. With GDB you might record execution for a short a minute or two, but with rr you can record everything, all the time. It's fast enough that you could record your every-day browsing sessions just in case you encounter a bug.

On the other hand, you are technically correct.

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