view contrib/relnotes @ 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

#!/usr/bin/env python3
"""Generate release notes from our commit log.

This uses the relnotes extension directives when they're available,
and falls back to our old pre-relnotes logic that used to live in the
release-tools repo.
"""
import argparse
import re
import subprocess

rules = {
    # keep
    r"\(issue": 100,
    r"\(BC\)": 100,
    r"\(API\)": 100,
    r"\(SEC\)": 100,
    # core commands, bump up
    r"(commit|files|log|pull|push|patch|status|tag|summary)(|s|es):": 20,
    r"(annotate|alias|branch|bookmark|clone|graft|import|verify).*:": 20,
    # extensions, bump up
    r"(mq|shelve|rebase):": 20,
    # newsy
    r": deprecate": 20,
    r": new.*(extension|flag|module)": 10,
    r"( ability|command|feature|option|support)": 10,
    # experimental
    r"hg-experimental": 20,
    r"(from|graduate).*experimental": 15,
    r"(hide|mark).*experimental": -10,
    # bug-like?
    r"(fix|don't break|improve)": 7,
    r"(not|n't|avoid|fix|prevent).*crash": 10,
    r"vulnerab": 10,
    # boring stuff, bump down
    r"^contrib": -5,
    r"debug": -5,
    r"help": -5,
    r"minor": -5,
    r"(doc|metavar|bundle2|obsolete|obsmarker|rpm|setup|debug\S+:)": -15,
    r"(check-code|check-commit|check-config|import-checker)": -20,
    r"(flake8|lintian|pyflakes|pylint)": -20,
    # cleanups and refactoring
    r"(clean ?up|white ?space|spelling|quoting)": -20,
    r"(flatten|dedent|indent|nesting|unnest)": -20,
    r"(typo|hint|note|comment|TODO|FIXME)": -20,
    r"(style:|convention|one-?liner)": -20,
    r"(argument|absolute_import|attribute|assignment|mutable)": -15,
    r"(scope|True|False)": -10,
    r"(unused|useless|unnecessar|superfluous|duplicate|deprecated)": -10,
    r"(redundant|pointless|confusing|uninitialized|meaningless|dead)": -10,
    r": (drop|remove|delete|rip out)": -10,
    r": (inherit|rename|simplify|naming|inline)": -10,
    r"(correct doc|docstring|document .* method)": -20,
    r"(abstract|factor|extract|prepare|split|replace| import)": -20,
    r": add.*(function|method|implementation|example)": -10,
    r": (move|extract) .* (to|into|from|out of)": -20,
    r": implement ": -5,
    r": use .* implementation": -20,
    r": use .* instead of": -20,
    # code
    r"_": -10,
    r"__": -5,
    r"\(\)": -5,
    r"\S\S\S+\.\S\S\S\S+": -5,
    # dumb keywords
    r"\S+/\S+:": -10,
    r"\S+\.\S+:": -10,
    # python compatibility
    r"[Pp]y(|thon) ?[23]": -20,
    r"pycompat": -20,
    r"(coerce|convert|encode) .*to (byte|sys|)(s|str|string)": -20,
    # tests
    r"^test(|s|ing|runner|-\S+):": -20,
    r"^(f|hghave|run-tests):": -20,
    r"add.* tests?": -20,
    r"(buildbot|fuzz|mock|ratchet)": -10,
    # drop
    r"^i18n-": -50,
    r"^i18n:.*(hint|comment)": -50,
    r"perf:": -50,
    r"Added.*for changeset": -50,
    r"^_": -50,
}

cutoff = 10
commits = []

groupings = [
    (r"util|parsers|repo|ctx|context|revlog|filelog|alias|cmdutil", "core"),
    (r"revset|template|ui|dirstate|hook|i18n|transaction|wire|vfs", "core"),
    (r"dispatch|exchange|localrepo|streamclone|color|pager", "core"),
    (r"hgweb|paper|coal|gitweb|monoblue|spartan", "hgweb"),
    (r"pull|push|revert|resolve|annotate|bookmark|branch|clone", "commands"),
    (r"commands|commit|config|files|graft|import|log|merge|patch", "commands"),
    (r"phases|status|summary|amend|tag|help|verify", "commands"),
    (r"rebase|mq|convert|eol|histedit|largefiles", "extensions"),
    (r"shelve|unshelve", "extensions"),
]


def wikify(desc):
    desc = desc.replace("(issue", "(Bts:issue")
    desc = re.sub(r"\b([0-9a-f]{12})\b", r"Cset:\1", desc)
    # stop ParseError from being recognized as a (nonexistent) wiki page
    desc = re.sub(r" ([A-Z][a-z]+[A-Z][a-z]+)\b", r" !\1", desc)
    # prevent wiki markup of magic methods
    desc = re.sub(r"\b(\S*__\S*)\b", r"`\1`", desc)
    return desc


def main():
    desc = "example: %(prog)s 4.7.2 --stoprev 4.8rc0"
    ap = argparse.ArgumentParser(description=desc)
    ap.add_argument(
        "startrev",
        metavar="REV",
        type=str,
        help=(
            "Starting revision for the release notes. This revision "
            "won't be included, but later revisions will."
        ),
    )
    ap.add_argument(
        "--stoprev",
        metavar="REV",
        type=str,
        default="@",
        help=(
            "Stop revision for release notes. This revision will be included,"
            " but no later revisions will. This revision needs to be "
            "a descendant of startrev."
        ),
    )
    args = ap.parse_args()
    fromext = subprocess.check_output(
        [
            "hg",
            "--config",
            "extensions.releasenotes=",
            "releasenotes",
            "-r",
            "only(%s, %s)" % (args.stoprev, args.startrev),
        ]
    ).decode("utf-8")
    # Find all release notes from un-relnotes-flagged commits.
    for entry in sorted(
        subprocess.check_output(
            [
                "hg",
                "log",
                "-r",
                "only(%s, %s) - merge()" % (args.stoprev, args.startrev),
                "-T",
                r"{desc|firstline}\n",
            ]
        )
        .decode("utf-8")
        .splitlines()
    ):
        desc = entry.replace("`", "'")

        score = 0
        for rule, val in rules.items():
            if re.search(rule, desc):
                score += val

        if score >= cutoff:
            commits.append(wikify(desc))
    # Group unflagged notes.
    groups = {}
    bcs = []
    apis = []

    for d in commits:
        if "(BC)" in d:
            bcs.append(d)
        if "(API)" in d:
            apis.append(d)
        for rule, g in groupings:
            if re.match(rule, d):
                groups.setdefault(g, []).append(d)
                break
        else:
            groups.setdefault("unsorted", []).append(d)
    print(fromext)
    # print legacy release notes sections
    for g in sorted(groups):
        print("\n=== %s ===" % g)
        for d in sorted(groups[g]):
            print(" * %s" % d)

    if bcs:
        print("\n=== Behavior Changes ===\n")

    for d in sorted(bcs):
        print(" * %s" % d)

    if apis:
        print("\n=== Internal API Changes ===\n")

    for d in sorted(apis):
        print(" * %s" % d)


if __name__ == "__main__":
    main()