Track local frames incrementally during execution
https://github.com/rust-lang/miri/pull/2646 currently introduces a performance regression. This change removes that regression, and provides a minor perf improvement.
The existing lazy strategy for tracking the span we want to display is as efficient as it is only because we often create a `CurrentSpan` then never call `.get()`. Most of the calls to the `before_memory_read` and `before_memory_write` hooks do not create any event that we store in `AllocHistory`. But data races are totally different, any memory read or write may race, so every call to those hooks needs to access to the current local span.
So this changes to a strategy where we update some state in a `Thread` and `FrameExtra` incrementally, upon entering and existing each function call.
Before:
```
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/backtraces/Cargo.toml
Time (mean ± σ): 5.532 s ± 0.022 s [User: 5.444 s, System: 0.073 s]
Range (min … max): 5.516 s … 5.569 s 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/mse/Cargo.toml
Time (mean ± σ): 831.4 ms ± 3.0 ms [User: 783.8 ms, System: 46.7 ms]
Range (min … max): 828.7 ms … 836.1 ms 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/serde1/Cargo.toml
Time (mean ± σ): 1.975 s ± 0.021 s [User: 1.914 s, System: 0.059 s]
Range (min … max): 1.939 s … 1.990 s 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/serde2/Cargo.toml
Time (mean ± σ): 4.060 s ± 0.051 s [User: 3.983 s, System: 0.071 s]
Range (min … max): 3.972 s … 4.100 s 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/slice-get-unchecked/Cargo.toml
Time (mean ± σ): 784.9 ms ± 8.2 ms [User: 746.5 ms, System: 37.7 ms]
Range (min … max): 772.9 ms … 793.3 ms 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/unicode/Cargo.toml
Time (mean ± σ): 1.679 s ± 0.006 s [User: 1.623 s, System: 0.055 s]
Range (min … max): 1.673 s … 1.687 s 5 runs
```
After:
```
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/backtraces/Cargo.toml
Time (mean ± σ): 5.330 s ± 0.037 s [User: 5.232 s, System: 0.084 s]
Range (min … max): 5.280 s … 5.383 s 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/mse/Cargo.toml
Time (mean ± σ): 818.9 ms ± 3.7 ms [User: 776.8 ms, System: 41.3 ms]
Range (min … max): 813.5 ms … 822.5 ms 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/serde1/Cargo.toml
Time (mean ± σ): 1.927 s ± 0.011 s [User: 1.864 s, System: 0.061 s]
Range (min … max): 1.917 s … 1.945 s 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/serde2/Cargo.toml
Time (mean ± σ): 3.974 s ± 0.020 s [User: 3.893 s, System: 0.076 s]
Range (min … max): 3.956 s … 4.004 s 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/slice-get-unchecked/Cargo.toml
Time (mean ± σ): 780.0 ms ± 5.3 ms [User: 740.3 ms, System: 39.0 ms]
Range (min … max): 771.2 ms … 784.5 ms 5 runs
Benchmark 1: cargo +miri miri run --manifest-path /home/ben/miri/bench-cargo-miri/unicode/Cargo.toml
Time (mean ± σ): 1.643 s ± 0.007 s [User: 1.584 s, System: 0.058 s]
Range (min … max): 1.635 s … 1.654 s 5 runs
```
(This change is marginal, but the point is that it avoids a much more significant regression)
- support pulling specific commit
- make rust-version update a separate commit to avoid confusing josh
- after pushing, check that we have a clear round-trip
interpret: support for per-byte provenance
Also factors the provenance map into its own module.
The third commit does the same for the init mask. I can move it in a separate PR if you prefer.
Fixes https://github.com/rust-lang/miri/issues/2181
r? `@oli-obk`
Add miri_alloc, miri_dealloc
`miri_alloc` and `miri_dealloc` are basically the same as `__rust_alloc` and `__rust_dealloc` respectively, but without the check for a global allocator.
This should allow bootstrapping an allocator in environments, where no fundamental way of allocating memory is available (`no_std` + `alloc` in Miri).
bootstrap: add support for running Miri on a file
This enables:
```
./x.py run src/tools/miri --stage 0 --args src/tools/miri/tests/pass/hello.rs
```
That can be super helpful for debugging.
Also avoid sharing the Miri sysroot dir with a system-wide (rustup-managed) installation of Miri.
Fixes https://github.com/rust-lang/rust/issues/76666
