Profiling Rust with execution time for each *line* of code?

Question

I have profiled my Rust code and see one processor-intensive function that takes a large portion of the time. Since I cannot break the function into smaller parts, I hope I can see which line in the function takes what portion of time. Currently I have tried CLion's Rust profiler, but it does not have that feature.

It would be best if the tool runs on MacOS since I do not have a Windows/Linux machine (except for virtualization).

P.S. Visual studio seems to have this feature; but I am using Rust. https://learn.microsoft.com/en-us/visualstudio/profiling/how-to-collect-line-level-sampling-data?view=vs-2017 It has:

Line-level sampling is the ability of the profiler to determine where in the code of a processor-intensive function, such as a function that has high exclusive samples, the processor has to spend most of its time.

Thanks for any suggestions!

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EDIT: With C++, I do see source code line level information. For example, the following toy shows that, the "for" loop takes most of the time within the big function. But I am using Rust...

Answer 1

Once compiled, "lines" of Rust do not exist. The optimiser does its job by completely reorganising the code you wrote and finding the minimal machine code that behaves the same as what you intended.

Functions are often inlined, so even measuring the time spent in a function can give incorrect results - or else change the performance characteristics of your program if you prevent it from being inlined to do so.