##// END OF EJS Templates
rust: fix unsound `OwningDirstateMap`...
rust: fix unsound `OwningDirstateMap` As per the previous patch, `OwningDirstateMap` is unsound. Self-referential structs are difficult to implement correctly in Rust since the compiler is free to move structs around as much as it wants to. They are also very rarely needed in practice, so the state-of-the-art on how they should be done within the Rust rules is still a bit new. The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense) of declaring self-referential structs. It is getting a lot attention and was improved very quickly when soundness issues were found in the past: rather than relying on our own (limited) review circle, we might as well use the de-facto common crate to fix this problem. This will give us a much better chance of finding issues should any new ones be discovered as well as the benefit of fewer `unsafe` APIs of our own. I was starting to think about how I would present a safe API to the old struct but soon realized that the callback-based approach was already done in `ouroboros`, along with a lot more care towards refusing incorrect structs. In short: we don't return a mutable reference to the `DirstateMap` anymore, we expect users of its API to pass a `FnOnce` that takes the map as an argument. This allows our `OwningDirstateMap` to control the input and output lifetimes of the code that modifies it to prevent such issues. Changing to `ouroboros` meant changing every API with it, but it is relatively low churn in the end. It correctly identified the example buggy modification of `copy_map_insert` outlined in the previous patch as violating the borrow rules. Differential Revision: https://phab.mercurial-scm.org/D12429

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lib.rs
70 lines | 2.1 KiB | application/rls-services+xml | RustLexer
// lib.rs
//
// Copyright 2018 Georges Racinet <gracinet@anybox.fr>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.
//! Python bindings of `hg-core` objects using the `cpython` crate.
//! Once compiled, the resulting single shared library object can be placed in
//! the `mercurial` package directly as `rustext.so` or `rustext.dll`.
//! It holds several modules, so that from the point of view of Python,
//! it behaves as the `cext` package.
//!
//! Example:
//!
//! ```text
//! >>> from mercurial.rustext import ancestor
//! >>> ancestor.__doc__
//! 'Generic DAG ancestor algorithms - Rust implementation'
//! ```
/// This crate uses nested private macros, `extern crate` is still needed in
/// 2018 edition.
#[macro_use]
extern crate cpython;
pub mod ancestors;
mod cindex;
mod conversion;
#[macro_use]
pub mod ref_sharing;
pub mod copy_tracing;
pub mod dagops;
pub mod debug;
pub mod dirstate;
pub mod discovery;
pub mod exceptions;
mod pybytes_deref;
pub mod revlog;
pub mod utils;
py_module_initializer!(rustext, initrustext, PyInit_rustext, |py, m| {
m.add(
py,
"__doc__",
"Mercurial core concepts - Rust implementation",
)?;
let dotted_name: String = m.get(py, "__name__")?.extract(py)?;
m.add(py, "ancestor", ancestors::init_module(py, &dotted_name)?)?;
m.add(py, "dagop", dagops::init_module(py, &dotted_name)?)?;
m.add(py, "debug", debug::init_module(py, &dotted_name)?)?;
m.add(
py,
"copy_tracing",
copy_tracing::init_module(py, &dotted_name)?,
)?;
m.add(py, "discovery", discovery::init_module(py, &dotted_name)?)?;
m.add(py, "dirstate", dirstate::init_module(py, &dotted_name)?)?;
m.add(py, "revlog", revlog::init_module(py, &dotted_name)?)?;
m.add(py, "GraphError", py.get_type::<exceptions::GraphError>())?;
Ok(())
});
#[cfg(not(any(feature = "python27-bin", feature = "python3-bin")))]
#[test]
#[ignore]
fn libpython_must_be_linked_to_run_tests() {
// stub function to tell that some tests wouldn't run
}