If you want something passable, most compilers have function prologue/epilogue hooks that you can write in plain code. Realistically, development and test syste

If you want something passable, most compilers have function prologue/epilogue hooks that you can write in plain code. Realistically, development and test systems are only going to target like 1 or 2 compilers, so it is not very much work. Unless you are distributing a source library and you want to get full-trace telemetry from customer systems in-development, that is probably all you really need to do. If you want to really zoom, you need to get the hooks inlined and probably just written in straight assembly. You then need to optimize your binary format and recording system. You then need to start optimizing your memory bandwidth usage when that becomes the bottleneck. Your overhead in the end is basically limited by memory bandwidth; you can only shovel so many tens of GB/s of logging into memory. Note that persistence has likely been infeasible for the last 2 or so orders of magnitude; RAM is likely the only storage consistently fast enough for the data rates you want to generate when doing this.