##// 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

File last commit:

r49857:c9f44fc9 stable
r49864:dd6b67d5 stable
Show More
status.rs
302 lines | 9.6 KiB | application/rls-services+xml | RustLexer
// status.rs
//
// Copyright 2019, Raphaël Gomès <rgomes@octobus.net>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.
//! Bindings for the `hg::status` module provided by the
//! `hg-core` crate. From Python, this will be seen as
//! `rustext.dirstate.status`.
use crate::{dirstate::DirstateMap, exceptions::FallbackError};
use cpython::{
exc::ValueError, ObjectProtocol, PyBytes, PyErr, PyList, PyObject,
PyResult, PyTuple, Python, PythonObject, ToPyObject,
};
use hg::dirstate::status::StatusPath;
use hg::{
matchers::{AlwaysMatcher, FileMatcher, IncludeMatcher},
parse_pattern_syntax,
utils::{
files::{get_bytes_from_path, get_path_from_bytes},
hg_path::{HgPath, HgPathBuf},
},
BadMatch, DirstateStatus, IgnorePattern, PatternFileWarning, StatusError,
StatusOptions,
};
use std::borrow::Borrow;
fn collect_status_path_list(py: Python, paths: &[StatusPath<'_>]) -> PyList {
collect_pybytes_list(py, paths.iter().map(|item| &*item.path))
}
/// This will be useless once trait impls for collection are added to `PyBytes`
/// upstream.
fn collect_pybytes_list(
py: Python,
iter: impl Iterator<Item = impl AsRef<HgPath>>,
) -> PyList {
let list = PyList::new(py, &[]);
for path in iter {
list.append(
py,
PyBytes::new(py, path.as_ref().as_bytes()).into_object(),
)
}
list
}
fn collect_bad_matches(
py: Python,
collection: &[(impl AsRef<HgPath>, BadMatch)],
) -> PyResult<PyList> {
let list = PyList::new(py, &[]);
let os = py.import("os")?;
let get_error_message = |code: i32| -> PyResult<_> {
os.call(
py,
"strerror",
PyTuple::new(py, &[code.to_py_object(py).into_object()]),
None,
)
};
for (path, bad_match) in collection.iter() {
let message = match bad_match {
BadMatch::OsError(code) => get_error_message(*code)?,
BadMatch::BadType(bad_type) => format!(
"unsupported file type (type is {})",
bad_type.to_string()
)
.to_py_object(py)
.into_object(),
};
list.append(
py,
(PyBytes::new(py, path.as_ref().as_bytes()), message)
.to_py_object(py)
.into_object(),
)
}
Ok(list)
}
fn handle_fallback(py: Python, err: StatusError) -> PyErr {
match err {
StatusError::Pattern(e) => {
let as_string = e.to_string();
log::trace!("Rust status fallback: `{}`", &as_string);
PyErr::new::<FallbackError, _>(py, &as_string)
}
e => PyErr::new::<ValueError, _>(py, e.to_string()),
}
}
pub fn status_wrapper(
py: Python,
dmap: DirstateMap,
matcher: PyObject,
root_dir: PyObject,
ignore_files: PyList,
check_exec: bool,
list_clean: bool,
list_ignored: bool,
list_unknown: bool,
collect_traversed_dirs: bool,
) -> PyResult<PyTuple> {
let bytes = root_dir.extract::<PyBytes>(py)?;
let root_dir = get_path_from_bytes(bytes.data(py));
let dmap: DirstateMap = dmap.to_py_object(py);
let mut dmap = dmap.get_inner_mut(py);
let ignore_files: PyResult<Vec<_>> = ignore_files
.iter(py)
.map(|b| {
let file = b.extract::<PyBytes>(py)?;
Ok(get_path_from_bytes(file.data(py)).to_owned())
})
.collect();
let ignore_files = ignore_files?;
// The caller may call `copymap.items()` separately
let list_copies = false;
let after_status = |res: Result<(DirstateStatus<'_>, _), StatusError>| {
let (status_res, warnings) =
res.map_err(|e| handle_fallback(py, e))?;
build_response(py, status_res, warnings)
};
match matcher.get_type(py).name(py).borrow() {
"alwaysmatcher" => {
let matcher = AlwaysMatcher;
dmap.with_status(
&matcher,
root_dir.to_path_buf(),
ignore_files,
StatusOptions {
check_exec,
list_clean,
list_ignored,
list_unknown,
list_copies,
collect_traversed_dirs,
},
after_status,
)
}
"exactmatcher" => {
let files = matcher.call_method(
py,
"files",
PyTuple::new(py, &[]),
None,
)?;
let files: PyList = files.cast_into(py)?;
let files: PyResult<Vec<HgPathBuf>> = files
.iter(py)
.map(|f| {
Ok(HgPathBuf::from_bytes(
f.extract::<PyBytes>(py)?.data(py),
))
})
.collect();
let files = files?;
let matcher = FileMatcher::new(files.as_ref())
.map_err(|e| PyErr::new::<ValueError, _>(py, e.to_string()))?;
dmap.with_status(
&matcher,
root_dir.to_path_buf(),
ignore_files,
StatusOptions {
check_exec,
list_clean,
list_ignored,
list_unknown,
list_copies,
collect_traversed_dirs,
},
after_status,
)
}
"includematcher" => {
// Get the patterns from Python even though most of them are
// redundant with those we will parse later on, as they include
// those passed from the command line.
let ignore_patterns: PyResult<Vec<_>> = matcher
.getattr(py, "_kindpats")?
.iter(py)?
.map(|k| {
let k = k?;
let syntax = parse_pattern_syntax(
&[
k.get_item(py, 0)?
.extract::<PyBytes>(py)?
.data(py),
&b":"[..],
]
.concat(),
)
.map_err(|e| {
handle_fallback(py, StatusError::Pattern(e))
})?;
let pattern = k.get_item(py, 1)?.extract::<PyBytes>(py)?;
let pattern = pattern.data(py);
let source = k.get_item(py, 2)?.extract::<PyBytes>(py)?;
let source = get_path_from_bytes(source.data(py));
let new = IgnorePattern::new(syntax, pattern, source);
Ok(new)
})
.collect();
let ignore_patterns = ignore_patterns?;
let matcher = IncludeMatcher::new(ignore_patterns)
.map_err(|e| handle_fallback(py, e.into()))?;
dmap.with_status(
&matcher,
root_dir.to_path_buf(),
ignore_files,
StatusOptions {
check_exec,
list_clean,
list_ignored,
list_unknown,
list_copies,
collect_traversed_dirs,
},
after_status,
)
}
e => Err(PyErr::new::<ValueError, _>(
py,
format!("Unsupported matcher {}", e),
)),
}
}
fn build_response(
py: Python,
status_res: DirstateStatus,
warnings: Vec<PatternFileWarning>,
) -> PyResult<PyTuple> {
let modified = collect_status_path_list(py, &status_res.modified);
let added = collect_status_path_list(py, &status_res.added);
let removed = collect_status_path_list(py, &status_res.removed);
let deleted = collect_status_path_list(py, &status_res.deleted);
let clean = collect_status_path_list(py, &status_res.clean);
let ignored = collect_status_path_list(py, &status_res.ignored);
let unknown = collect_status_path_list(py, &status_res.unknown);
let unsure = collect_status_path_list(py, &status_res.unsure);
let bad = collect_bad_matches(py, &status_res.bad)?;
let traversed = collect_pybytes_list(py, status_res.traversed.iter());
let dirty = status_res.dirty.to_py_object(py);
let py_warnings = PyList::new(py, &[]);
for warning in warnings.iter() {
// We use duck-typing on the Python side for dispatch, good enough for
// now.
match warning {
PatternFileWarning::InvalidSyntax(file, syn) => {
py_warnings.append(
py,
(
PyBytes::new(py, &get_bytes_from_path(&file)),
PyBytes::new(py, syn),
)
.to_py_object(py)
.into_object(),
);
}
PatternFileWarning::NoSuchFile(file) => py_warnings.append(
py,
PyBytes::new(py, &get_bytes_from_path(&file)).into_object(),
),
}
}
Ok(PyTuple::new(
py,
&[
unsure.into_object(),
modified.into_object(),
added.into_object(),
removed.into_object(),
deleted.into_object(),
clean.into_object(),
ignored.into_object(),
unknown.into_object(),
py_warnings.into_object(),
bad.into_object(),
traversed.into_object(),
dirty.into_object(),
][..],
))
}