Mercurial > hg
view tests/test-releasenotes-parsing.t @ 49000:dd6b67d5c256 stable
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
author | Raphaël Gomès <rgomes@octobus.net> |
---|---|
date | Tue, 05 Apr 2022 10:55:28 +0200 |
parents | 3fff6f30bd7f |
children |
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#require fuzzywuzzy $ cat >> $HGRCPATH << EOF > [extensions] > releasenotes= > EOF Bullet point with a single item spanning a single line $ hg debugparsereleasenotes - << EOF > New Features > ============ > > * Bullet point item with a single line > EOF section: feature bullet point: paragraph: Bullet point item with a single line Bullet point that spans multiple lines. $ hg debugparsereleasenotes - << EOF > New Features > ============ > > * Bullet point with a paragraph > that spans multiple lines. > EOF section: feature bullet point: paragraph: Bullet point with a paragraph that spans multiple lines. $ hg debugparsereleasenotes - << EOF > New Features > ============ > > * Bullet point with a paragraph > that spans multiple lines. > > And has an empty line between lines too. > With a line cuddling that. > EOF section: feature bullet point: paragraph: Bullet point with a paragraph that spans multiple lines. paragraph: And has an empty line between lines too. With a line cuddling that. Multiple bullet points. With some entries being multiple lines. $ hg debugparsereleasenotes - << EOF > New Features > ============ > > * First bullet point. It has a single line. > > * Second bullet point. > It consists of multiple lines. > > * Third bullet point. It has a single line. > EOF section: feature bullet point: paragraph: First bullet point. It has a single line. bullet point: paragraph: Second bullet point. It consists of multiple lines. bullet point: paragraph: Third bullet point. It has a single line. Bullet point without newline between items $ hg debugparsereleasenotes - << EOF > New Features > ============ > > * First bullet point > * Second bullet point > And it has multiple lines > * Third bullet point > * Fourth bullet point > EOF section: feature bullet point: paragraph: First bullet point bullet point: paragraph: Second bullet point And it has multiple lines bullet point: paragraph: Third bullet point bullet point: paragraph: Fourth bullet point Sub-section contents are read $ hg debugparsereleasenotes - << EOF > New Features > ============ > > First Feature > ------------- > > This is the first new feature that was implemented. > > And a second paragraph about it. > > Second Feature > -------------- > > This is the second new feature that was implemented. > > Paragraph two. > > Paragraph three. > EOF section: feature subsection: First Feature paragraph: This is the first new feature that was implemented. paragraph: And a second paragraph about it. subsection: Second Feature paragraph: This is the second new feature that was implemented. paragraph: Paragraph two. paragraph: Paragraph three. Multiple sections are read $ hg debugparsereleasenotes - << EOF > New Features > ============ > > * Feature 1 > * Feature 2 > > Bug Fixes > ========= > > * Fix 1 > * Fix 2 > EOF section: feature bullet point: paragraph: Feature 1 bullet point: paragraph: Feature 2 section: fix bullet point: paragraph: Fix 1 bullet point: paragraph: Fix 2 Mixed sub-sections and bullet list $ hg debugparsereleasenotes - << EOF > New Features > ============ > > Feature 1 > --------- > > Some words about the first feature. > > Feature 2 > --------- > > Some words about the second feature. > That span multiple lines. > > Other Changes > ------------- > > * Bullet item 1 > * Bullet item 2 > EOF section: feature subsection: Feature 1 paragraph: Some words about the first feature. subsection: Feature 2 paragraph: Some words about the second feature. That span multiple lines. bullet point: paragraph: Bullet item 1 bullet point: paragraph: Bullet item 2 Warn user in case of unexpected block while parsing $ hg init relnotes-warn $ cd relnotes-warn $ touch feature1 $ hg -q commit -A -l - << EOF > commit 1 > > .. feature:: > > new feature added. > some words about the feature. > EOF $ hg releasenote -r . changeset a4251905c440: unexpected block in release notes directive feature New Features ============ * new feature added. some words about the feature. $ cd ..