* Miri runs the program as a platform-independent interpreter, so the program
has no access to most platform-specific APIs or FFI. A few APIs have been
implemented (such as printing to stdout) but most have not: for example, Miri
- currently does not support concurrency, or SIMD, or networking.
+ currently does not support SIMD or networking.
+* Miri currently does not check for data-races and most other concurrency-related
+ issues.
[rust]: https://www.rust-lang.org/
[mir]: https://github.com/rust-lang/rfcs/blob/master/text/1211-mir.md
echo "Installing latest nightly with Miri: $MIRI_NIGHTLY"
rustup set profile minimal
rustup default "$MIRI_NIGHTLY"
-
rustup component add miri
-cargo miri setup
cargo miri test
```
-We use `cargo miri setup` to avoid getting interactive questions about the extra
-setup needed for Miri.
-
### Common Problems
When using the above instructions, you may encounter a number of confusing compiler
This means the sysroot you are using was not compiled with Miri in mind. This
should never happen when you use `cargo miri` because that takes care of setting
-up the sysroot. If you are using `miri` (the Miri driver) directly, see
-[below][testing-miri] for how to set up the sysroot.
+up the sysroot. If you are using `miri` (the Miri driver) directly, see the
+[contributors' guide](CONTRIBUTING.md) for how to use `./miri` to best do that.
## Miri `-Z` flags and environment variables
for cryptographic use! Do not generate secret keys in Miri or perform other
kinds of cryptographic operations that rely on proper random numbers.
* `-Zmiri-track-alloc-id=<id>` shows a backtrace when the given allocation is
- being allocated. This helps in debugging memory leaks.
+ being allocated or freed. This helps in debugging memory leaks and
+ use after free bugs.
* `-Zmiri-track-pointer-tag=<tag>` shows a backtrace when the given pointer tag
is popped from a borrow stack (which is where the tag becomes invalid and any
future use of it will error). This helps you in finding out why UB is
* `MIRI_TEST_FLAGS` (recognized by the test suite) defines extra flags to be
passed to Miri.
+The following environment variables are internal, but used to communicate between
+different Miri binaries, and as such worth documenting:
+
+* `MIRI_BE_RUSTC` when set to any value tells the Miri driver to actually not
+ interpret the code but compile it like rustc would. This is useful to be sure
+ that the compiled `rlib`s are compatible with Miri.
+
## Contributing and getting help
If you want to contribute to Miri, great! Please check out our
* [The Unix allocator calling `posix_memalign` in an invalid way](https://github.com/rust-lang/rust/issues/62251)
* [`getrandom` calling the `getrandom` syscall in an invalid way](https://github.com/rust-random/getrandom/pull/73)
* [`Vec`](https://github.com/rust-lang/rust/issues/69770) and [`BTreeMap`](https://github.com/rust-lang/rust/issues/69769) leaking memory under some (panicky) conditions
-* [Memory leak in `beef`](https://github.com/maciejhirsz/beef/issues/12)
-* [Invalid use of undefined memory in `EbrCell`](https://github.com/Firstyear/concread/commit/b15be53b6ec076acb295a5c0483cdb4bf9be838f#diff-6282b2fc8e98bd089a1f0c86f648157cR229)
+* [`beef` leaking memory](https://github.com/maciejhirsz/beef/issues/12)
+* [`EbrCell` using uninitialized memory incorrectly](https://github.com/Firstyear/concread/commit/b15be53b6ec076acb295a5c0483cdb4bf9be838f#diff-6282b2fc8e98bd089a1f0c86f648157cR229)
+* [TiKV performing an unaligned pointer access](https://github.com/tikv/tikv/issues/7613)
+* [`servo_arc` creating a dangling shared reference](https://github.com/servo/servo/issues/26357)
+* [TiKV constructing out-of-bounds pointers (and overlapping mutable references)](https://github.com/tikv/tikv/pull/7751)
Violations of [Stacked Borrows] found that are likely bugs (but Stacked Borrows is currently just an experiment):
* [`LinkedList` creating overlapping mutable references](https://github.com/rust-lang/rust/pull/60072)
* [`Vec::push` invalidating existing references into the vector](https://github.com/rust-lang/rust/issues/60847)
* [`align_to_mut` violating uniqueness of mutable references](https://github.com/rust-lang/rust/issues/68549)
-* [Aliasing mutable references in `sized-chunks`](https://github.com/bodil/sized-chunks/issues/8)
+* [`sized-chunks` creating aliasing mutable references](https://github.com/bodil/sized-chunks/issues/8)
* [`String::push_str` invalidating existing references into the string](https://github.com/rust-lang/rust/issues/70301)
+* [`ryu` using raw pointers outside their valid memory area](https://github.com/dtolnay/ryu/issues/24)
+* [ink! creating overlapping mutable references](https://github.com/rust-lang/miri/issues/1364)
+* [TiKV creating overlapping mutable reference and raw pointer](https://github.com/tikv/tikv/pull/7709)
## License