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view tests/test-minirst.py @ 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 | aaff3bc75306 |
children | 6000f5b25c9b |
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from __future__ import absolute_import, print_function from mercurial import minirst from mercurial.utils import stringutil def debugformat(text, form, **kwargs): blocks, pruned = minirst.parse(text, **kwargs) if form == b'html': print("html format:") out = minirst.format(text, style=form, **kwargs) else: print("%d column format:" % form) out = minirst.format(text, width=form, **kwargs) print("-" * 70) print(out[:-1].decode('utf8')) if kwargs.get('keep'): print("-" * 70) print(stringutil.pprint(pruned).decode('utf8')) print("-" * 70) print() def debugformats(title, text, **kwargs): print("== %s ==" % title) debugformat(text, 60, **kwargs) debugformat(text, 30, **kwargs) debugformat(text, b'html', **kwargs) paragraphs = b""" This is some text in the first paragraph. A small indented paragraph. It is followed by some lines containing random whitespace. \n \n \nThe third and final paragraph. """ debugformats('paragraphs', paragraphs) definitions = b""" A Term Definition. The indented lines make up the definition. Another Term Another definition. The final line in the definition determines the indentation, so this will be indented with four spaces. A Nested/Indented Term Definition. """ debugformats('definitions', definitions) literals = br""" The fully minimized form is the most convenient form:: Hello literal world In the partially minimized form a paragraph simply ends with space-double-colon. :: //////////////////////////////////////// long un-wrapped line in a literal block \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ :: This literal block is started with '::', the so-called expanded form. The paragraph with '::' disappears in the final output. """ debugformats('literals', literals) lists = b""" - This is the first list item. Second paragraph in the first list item. - List items need not be separated by a blank line. - And will be rendered without one in any case. We can have indented lists: - This is an indented list item - Another indented list item:: - A literal block in the middle of an indented list. (The above is not a list item since we are in the literal block.) :: Literal block with no indentation (apart from the two spaces added to all literal blocks). 1. This is an enumerated list (first item). 2. Continuing with the second item. (1) foo (2) bar 1) Another 2) List Line blocks are also a form of list: | This is the first line. The line continues here. | This is the second line. Bullet lists are also detected: * This is the first bullet * This is the second bullet It has 2 lines * This is the third bullet """ debugformats('lists', lists) options = b""" There is support for simple option lists, but only with long options: -X, --exclude filter an option with a short and long option with an argument -I, --include an option with both a short option and a long option --all Output all. --both Output both (this description is quite long). --long Output all day long. --par This option has two paragraphs in its description. This is the first. This is the second. Blank lines may be omitted between options (as above) or left in (as here). The next paragraph looks like an option list, but lacks the two-space marker after the option. It is treated as a normal paragraph: --foo bar baz """ debugformats('options', options) fields = b""" :a: First item. :ab: Second item. Indentation and wrapping is handled automatically. :c\:d: a key with colon :efg\:\:hh: a key with many colon Next list: :small: The larger key below triggers full indentation here. :much too large: This key is big enough to get its own line. """ debugformats('fields', fields) containers = b""" Normal output. .. container:: debug Initial debug output. .. container:: verbose Verbose output. .. container:: debug Debug output. """ debugformats('containers (normal)', containers) debugformats('containers (verbose)', containers, keep=[b'verbose']) debugformats('containers (debug)', containers, keep=[b'debug']) debugformats( 'containers (verbose debug)', containers, keep=[b'verbose', b'debug'] ) roles = b"""Please see :hg:`add`.""" debugformats('roles', roles) sections = b""" Title ===== Section ------- Subsection '''''''''' Markup: ``foo`` and :hg:`help` ------------------------------ """ debugformats('sections', sections) admonitions = b""" .. note:: This is a note - Bullet 1 - Bullet 2 .. warning:: This is a warning Second input line of warning .. danger:: This is danger """ debugformats('admonitions', admonitions) comments = b""" Some text. .. A comment .. An indented comment Some indented text. .. Empty comment above """ debugformats('comments', comments) data = [ [b'a', b'b', b'c'], [b'1', b'2', b'3'], [b'foo', b'bar', b'baz this list is very very very long man'], ] rst = minirst.maketable(data, 2, True) table = b''.join(rst) print(table.decode('utf8')) debugformats('table', table) data = [ [b's', b'long', b'line\ngoes on here'], [b'', b'xy', b'tried to fix here\n by indenting'], ] rst = minirst.maketable(data, 1, False) table = b''.join(rst) print(table.decode('utf8')) debugformats('table+nl', table)